If you're not interested in earning points with Qantas or Virgin Blue in Australia then there's not that many worthwhile credit cards available.

Your best option would probably be one of the American Express cards in Australia then. AMEX has pretty good acceptance in Australia, and the Membership Rewards Ascent program lets you transfer to a number of airlines (AirNZ, Cathay Pacific, Singapore Airlines, Thai, Virgin Blue and Virgin Atlantic) along with transfers to hotel programs as well. I've got the AMEX Platinum Credit Card and found it good with the 1.5 points per dollar - though the annual fee's probably not worthwhile if you're not able to take advantage of the included domestic flight or hotel stay.

Apart from AMEX the selection's pretty limited. Westpac has a Singapore Airlines Krisflyer Visa/AMEX combo available that has decent earning and other benefits if you're interested in Krisflyer. Citibank has an Emirates Mastercard as well that earns 1.5 points per dollar and includes some other benefits when flying on Emirates.

That's pretty much it overall, and for me the AMEX is my primary card, but you will still need a Mastercard/Visa for those locations that don't take AMEX yet.