How do you end Good ol boy club?

Not a whole lot you can do, especially IF you're the outsider. I had a similar situation with the group I joined in Iraq. The unit had come from Arkansas and I was from South Carolina. I could do no right, in their eyes. I even had a Specialist that was friends with the Sergeant Major, probably in more ways than one. She asked me to do certain jobs, that she probably wouldn’t give to others or do herself, because she informed me, she was passing information from the Sergeant Major...I knew better. I lived thru it and parted ways after we got back...have not spoken or seen any of them since.

You don't. You can't stop people from having friends.

That being said, if you can show a bona fide case of discrimination then you can bring that up the chain.

But before ANY of that, maybe just sit down with your first line and let him/her know that you feel like you are on the outside looking in and would like to be a full member of the team.

Really hard, I saw a USAR unit where the Commander and 1/2 the unit worked together in his business stateside. Caused many problems