There is nothing for the school to correct at this point.
With your son, go back to basics, using the same criteria we should use with younger kids. It is not tattling if you are protecting someone from real harm, including yourself.
You tell an adult EVERY time something is happening that will hurt someone. That means that if someone is being touched in any way (your son was) or if there are words said that will lead to real harm (such as vicious rumors spreading) then an adult needs to be involved. Your son was absolutely right to involve adults at home and at school when he was being assaulted. But being called a tattle-tale? Doesn't rise to the level of real harm to him, frankly, though that is hard for him to hear and for you to see.
Yes, it is upsetting and nasty of the kids who are doing it. But have you pointed out to your son that he very likely has saved other kids from being beaten up on by these two thugs? Your son probably was only their latest scapegoat; they surely have bullied, and will bully, other kids, but now they are on the school's radar. He will not get whispers of "good job" from the kids who were already afraid of these bullies, but sadly he will get those whispers of "snitch" from kids who are themselves jerks. He is old enough now to start learning -- and he has to learn it from you -- that doing the right thing can come at a real cost to the person who does it.
Please work to ensure that this does not drive him inside himself and make him clam up from now on whenever anything is wrong at school. That would be a horrible outcome. He may need to see the school counselor a few times -- alone, and confidentially, without the counselor coming to pull him out of class or calling for him over the intercom. The other kids don't need to know if he wants to talk to the counselor. The counselor also should not be grilling him about "who's picking on you for telling about the bullying" -- any discussions between them should simply be about supporting him in his correct choice, and giving him tools to handle the pressure he feels right now.
While the school should not have put him in the same room as the bullies, at least the school took action. It was right to take away the one thing that apparently really hurts the one boy (his role as a school patrol). That was a good call on the school's part. While I agree your son should have been seen separately from the other boys, I would disagree that it was handled badly overall. I'm not sure you understand how often schools do nothing, or do so little that the bullies keep on going.
A close friend's son -- same grade as your own son -- was being badly bullied the first two weeks of this school year, being slapped and punched in the head every single day; thrown into lockers; thrown into music stands; and so on, and the teacher "never saw anything" and only said "He needs to advocate for himself" when the parents vigorously complained. The teacher, principal and school did not call in the bullies and their parents UNTIL the day the mom e-mailed the school district in the morning and took her son to the police station in the afternoon (because that same day, the bullies again punched her son at school). The mom said she was not at the point of filing charges but wanted to be on the record with the police that this was occurring. The mom didn't ask for it, but a cop then went directly to the school that same afternoon and told the school administrators that if things did not stop immediately, he would advise the family to file charges and he planned to visit the families of the bullies.
So your son's school at least reacted -- rather than you having to send a ton of e-mails that get no response (which happened to my friends) and having to involve the cops. By the way, if these boys continue to try to harass your son, DO involve the cops. See if there is a "school resource officer" (that's what they're called here) who goes to schools and handles school issues.
One last thing: You moved very recently. Does your son have some extracurricular activiites yet? I would get him into some fun activities ASAP -- ones that are not affiliated with school! He needs to have friends outside school, who do not attend the same school, and who know him for himself and as a Boy Scout or a soccer player or an actor or artist or computer programmer or whatever his interest is. Find him activities that are based on his interests, so he is not focusing on himself and his troubles at school, but on the fun of the activity. Do not tell him, though that "You need an activity to take your mind off school" or whatever -- that will only make him see the activity as related to his troubles, not as something you're offering that's based on his interests.