International and domestic are separate. It sounds like you are flying domestic on TAM from GIG to GRU, so no lounge access based on *G. An exception may be if you are continuing onwards to a foreign destination on the same flight number via TAM in which case TAM may consider the departure from GIG to be an international flight. Don't know if TAM does this. UA 860 does so. You aren't on a code share and actually on UA metal, are you?