The UK site doesn't say anything about this, although it does mention Continental, NorthWest and BMI (in addition to Priority Pass benefits).

In general, I have found lounge access in the U.S. to be difficult and confusing for people used to the way things operate in much of the rest of the world. Last time I took a domestic flight in the U.S. I was very surprised to discover that as an F passenger (on United) I did not get lounge access. I dare say that to American FT'ers this is all very obvious. The only lounges to which I did have access (e.g. through Priority Pass) were in distant terminals and really not worth the bother of getting to. Fortunately, the Wolfgang Puck pizza available at LAX is better than almost any lounge food and the departue was on time so I survived.

I also recall the culture shock of the announcment at the gate "Information for those passengers waiting for upgrades: our first class cabin has checked in full..." - this was when I felt rather smug as I was "part of the problem, not the solution", having actually paid with money for my ticket. I don't think I have ever heard such an announcement outside the U.S. as everyone pretty much knows what cabin they will be in before they get to the airport.