It seems as though after George was killed, all bets were off on the one big happy family approuch. The Bonnanos had their own problems and it wasn't like they could just send someone up there every time they wanted to talk about something with post 9/11 immigration and border control, etc..

Plus, Vito did his time and pretty much kept his mouth shut and the Bonnanos probably said "enough"

"In onore della Famiglia la Famiglia e' aperta"