If you are flying a lot (a definition of a lot might be useful) then BA might be the go to program depending on your fare class. You do need a non-Australian address to join BA Executive Club. SYD-SIN/CGK earns 35 tier points each way at least on Qantas. More for flexible economy. 300, 600 and 1500 tier points to progress up the levels. So Qantas Silver equivalent after 9 flights in discount economy. Qantas is 30 SC, each way for the same routes. 10 flights to get Silver and gold, but fewer flight for platinum. Less flights to keep all levels with Qantas.
AA is miles based and I'm not as familiar with those requirements. Hopefully someone else will chip in.
Edit: Agree that as bronze you have an extremely small chance of an upgrade. Not as small as my chance to quantum tunnel through a wall, but close.