There is a lot of inaccurate information in this thread. The OP is correct that *G on a foreign carrier is sufficient to permit access to US clubs. It does not require an international itinerary, only US-based *G have that rule. So, OP can access the PHL clubs in general. The club in A terminal is an exception, because it is considered to be an international departures Envoy lounge only. It isn't a normal club at all.

So the choices come down to big club between B/C and the small club in F. The big club is nicer, but the small club is better located for his departing flight. I generally prefer to hang out in the B/C club.

I've only been in the RCC a couple of times, but enough to determine that I prefer the B/C club. You can also get "free" beer and wine in the US club.