I know that as a Plat I can use any ST lounge when I am flying on an international ticket. What I am wondering is- if I am FB plat, going on an AF flight and there is an AF lounge- am I still free to use any ST lounge I want at the airport or would, say, the Alitalia lounge refer me to go to the AF lounge since I am flying with them?

I recently had opportunity to visit a few ST lounges at NRT and all of them let me in although the KAL lounge gave me a strange look and took a long time writing down my info. To my surprise KAL was actually the worst of the lounges- when I was there there was no food except for some crackers and the lounge itself was very boring and outdated. It's possible there weren't any KE flights going out and that's why the elections were so poor but still surprising. Next I tried AF lounge- it was a lot more modern with great seating and nice bar chairs in red/white. They had a small selection of snacks and the standard variety of drinks. Finally moved to new NW lounge next door- a pleasant surprise. It was large and part of it almost looked like an open kitchen restaurant. There were quite a few snacks including sushi, sandwiches, kimbap. Free wireless without password.

All in all I thought NRT would have some of the better lounges such as in SIN or KUL but I guess they belong to other non Skyteam airlines such as ANA. Was pleasantly surprised by NW lounge however as it's certainly a stepup from the US Worldclubs.