FWIW
The Aussie fuel regulations were founded on the "sub-divide and conquer" principle. i.e. the regs basically only say that you must carry 'an appropriate quantitiy of fuel for the flight', without giving a further regulatory definition (remember, the CAAP's are not strictly legally binding, though they do provide 'expert advice'). This paves the way essentially for each and every company in Australia to have it's own interpretation of 'appropriate quantity' via the legally binding fuel policy pages in each individual ops manual (take a close look, its surprising how much this can sometimes vary between all manner of GA and bigger companies).
So, Mutt, strictly speaking, there is no Australia wide fuel policy, but as a generalisation the CAAP's (Civil Aviation Advisory Publication) usually hold true with:
Fixed reserve: 45 min
Variable reserve: 10% for turbine, 15% for piston
extra holding as required by weather, traffic notam (eg 20 mins for most of us @ SY, differs at different airports at different times), etc.