According to the OW website, QR still uses the Thai Royal Orchid lounge.
However, there appears to be a wide choice of OW lounges (some with restricted times):
- British Airways Lounge (7:15-10:30)
- Cathay Pacific First and Business Class Lounge, Concourse G (Mon/Wed: 05:30 - 19:30; Thu/Sun: 05:30 - 22:00; Tue/Fri/Sat: 05:30 - 00:30)
- Cathay Pacific First and Business Class Lounge, Concourse D (05:30 - 18:30, closed between 12:00 - 13:00)
- Japan Airlines Sakura Lounge (05:45-08:30,18:00-23:30)
- Qantas Business Lounge (13:30 to 17:00 Mon / Wed / Fri / Sat 13:30 to 21:00 Tue/ Thur / Sun)