There is no such program as *G. (That's what you have listed as your program, but it can't be.) *G is something you get from a *A member airline. You are *G only as an adjunct to having status in a particular *A member airline. The program you belong to is not *G, it is some member airline that then gives you *G benefits. (And which benefits those are, exactly, depends on which *A member airline that is!)

So what happens if you get your *A status through an airline in Greece (Aegean was the one being mentioned in the message you replied to)? Isn't flying within the USA "international" from a Greek perspective??? "Domestic" for a Greek airline is flying within Greece, not flying within the USA!