Apply in Syd if you want to stay in Brisbane? No. Because you will only be offered a position in Sydney and then will either need to move to Sydney or reject the job offer. I think you will be wasting your time to be honest. If you want to be in Brisbane wait until they recruit for Brisbane base. Transfers to other bases are only available when there are vacancies in those bases. So if you start in Sydney and go on the transfer list it will be the same wait as if you just stayed in Brisbane and waited for recruitment there to happen.
There are no backdoors for getting into Brisbane base, so just apply for there directly.