My wife and I recently booked a Japan holiday with our QFF points. We used the Qantas website to book this and found the process quite simple with a lot of availability.
My wife is a Qantas Club Member and we only just realised that we are not able to gain entry to the lounge pre flight due to our flight number… Because there is no QF in front of the flight number we are not eligible. Even though we booked using Qantas points through the Qantas website and we both are Qantas FF members and she is a Qantas club member we still cant access the lounge.
Well any option would involve a cost of some sort. If you hold an AMEX card with lounge passes or unlimited lounge access, you could enter the AMEX Sydney lounge. OR paying to get into the House lounge (formerly etihad lounge).
The most straightforward way next time is to book QF or JQ flight numbers and/or use your points for business class flights which come with lounge access.