Right now all Eastern FO's are starting in SYD. That hasn't always been the case; it depends on what vacancies are at each base.
Most of the new Qlink recruits are going to Sunstate, because that's where the vacancies are.
AFAIK, the only base in the Qlink network that has a waiting list is Melbourne. It is a long list. Right now you'll be waiting at least three years before getting a Melbourne base; probably longer.
That timeframe may change. There aren't any pending retirements, but there are three Q Cadets and at least one LOI holder who are waiting for their Mainline start dates (in sh'allah). Also, there may be resignations and (god forbid) there may be expansion out of Melbourne.
If any of the above happen, then there will be vacancies in MEL. About the only one that I'd be betting on right now would be resignations.
Sorry I can't paint a better picture.
DIVOSH!