Tightarse, with fines and taxes, the opportunity to efficiently use points in Australia are very limited. You may actually want to pay for some sectors (eg flying SYD-ADL, currently on JQ for $89, whereas you'd probably need 12,000 pts + $50 or so in fines & taxes).
I'd suggest the following:
SYD-ADL - pay for a fare
ADL-AYQ (via Alice Springs) - 12,000 pts + about $100 in taxes
AYQ-PER - 12,000 pts + about $50 in taxes
PER-BME - 12,000 pts + about $50 in taxes
BME-SYD (direct or via MEL) 18,000 pts + about $50 in taxes ($100 via MEL) (if via PER will cost 25,000 pts + $100 or so in taxes).
All up you're up for a fare from SYD-ADL + 54,000 pts + ~$250 in taxes and charges. (or 66,000 pts + $300 in taxes and charges)
Compared to 2000 when it would cost 30,000 pts and $6.80 in taxes and charges!!