I know; I just wanted to point out that a starting point to answer that question could be: Which frequent flyer program allows me to book Award flights to Australia (e.g. has plenty availability), and then look for which credit cards and/or bank accounts can you use for that frequent flyer program.

And when it comes to availability: AF/KL is not good, as they don't fly directly to Australia and depend on connecting flights on MH or KE. BA on the other hand does, so it might be the case that it's relatively easy to get flights.

Main purpose of the OP was to not only collect points/Miles, but to use them for flights to Australia.