Yes, Vito was expressing, perfectly, the Sicilian attitude that family isn't everything--it's the only thing--and that government comes last. He wasn't being unpatriotic, just Sicilian. Plus, he had a strong dose of cynicism about government, too--most emphatically expressed in his speech to Bonasera.
Vito wasn't anti-American. He was distrustful of government, because he realized, from his own experiences, that government doesn't run itself--it's made up of men who make decisions, and are therefore weak, corrupt, unjust, venal, etc.