Hey Belle,
Do you mean you were successful after medical etc and been offered a position waiting next ground school? Or are you just waiting for the next recruitment day?
Of course if you were at MEL or PER you would obviously need to move. That would need to be an important factor in your decision.
Brisbane will certainly have opportunities eventually, it is only natural, and I know some staff have recently transferred there but it may be some time till that comes up.
I would ensure you speak to a recruitment officer because you make any decisions such as removing your current application for Brisbane.