When in Rome...
Australian Hotel Hospitality jobs pay a much higher minimum wage than their USA equivalent counterparts. Tipping is not expected here, and indeed the smallest amount that folds is $5. This is the real reason the $1 bill will not vanish from the USA for quite some time. It's easier to hand over a few folded bills than a few coins. Much more discrete.
For something that is so common in the USA, discussing tipping certainly is a taboo subject i've noticed.
If you really want to tip in Australia, it is of course not shunned. Tip for excellent service, after all, that's what it should be for IMHO (and I always to tip for said reason).