Amex Australia now offer a fee-free Velocity card: the 'Escape', and fee-free Qantas credit card: the 'Discovery'.

Both offer 1 point per $1, enhanced to 2 points on the relevant airline spend.

As a Brit recently moved to Australia I like no-fee cards, so I have compared these cards for which offers the best value (purely on a monetary basis - not accounting for other virtues of QFF vs. Velocity).

Here are the results (expressed in % value back per $ spend):

Points value (%) Qantas Velocity
MEL-SYD (Econ) 1.68% 1.45%
MEL-SIN (Econ) 2.47% 1.74%
MEL-SIN (Bus) 3.84% 2.07%
MEL-LHR (Econ) 2.25% 2.03%
MEL-LHR (Bus) 4.01% 3.66%

Here are my main assumptions:
General spend pa: $20K
Relevant airline spend pa: $2K
All QF Econ tickets: Qantas Super Saver (Red e-deal for MEL-SYD)
All VA Econ tickets: Economy V Saver (Economy Saver for MEL-SYD)
All QF Bus tickets: Exclusive Business
All VA Bus tickets: Business Deal (operated by Etihad/Singapore)
All trips booked for 16-23 Oct 2013, prices as of 17 Dec 2012

Hope that's useful, happy earning!