SFO-SJC- sorry I don't have detailed answers, but here are some observations:

I just flew home from BWI alst weekend and was able to use the USAirClub in one terminal even though I was flying Southwest out of another. I came prepared with the PriorityPass guide in case the people at Security hadn't seen a PriorityPass- it lists every lounge you can use. I didn't need it.

My experiences so far: USAir Club at BWI- open bar. ServisAir lounge at LHR- open bar, coin-operated Internet access- but not too expensive. There was a Kuwaiti Airways lounge nearby- no alcohol. (The booklet tells you what you can get at each club.)

From what I could tell, there are no Admiral's Club lounges in the system. Unfortunate, since AA is my primary airline. Still, I'm happy with the deal. Looks like most of the time I'll be able to find someplace to hang out other than the gate area.