As others have said the QF First lounge in SYD lounge sometimes gets busy but rarely to capacity (that I have seen and I'm there about once a month) but it does seem that The House has now been added, I imagine (and this is guesswork) that it will be for business class passengers rather than first / emeralds because nobody would give up the QF First lounge and by my understanding OneWorld rules would prevent QF from denying access unless they went down a CCR type route, I'm not flying BA for a couple of weeks but will update!