You might as well try, you never know. My wife and I retruned from IAD in August travelling F on a 2-4-1 avios redemption. We had two teenagers with us travelling in Y and the lounge dragon at first seemed relucant to let them into the BA lounge with us "as I think the rules have changed and first passengers cannot guest anyone in" - which is incorrect.

I had the oneworld web page ready with the rules showing that F passengers could guest one person each, but she eventually said "OK, I guess it will be ok since we are not too busy". I didn't push it to correct her, just accepted her graciousness . She then asked if we would be having the F dining this evening and I said yes, expecting her to say it would only be for myself and my wife - which WOULD be correct - but she said we could all have F dining when we were ready, and we did ! The F dining room was actually quite busy when we did sit down to eat, so that was a win for us! They were a bit stingy with the wines during service, had to ask for top ups and a port but got there in the end.