There's a list of teachers in Queensland here:
There's some description of what they teach - several mention adult classes and have website links.
The Brisbane Dance Centre lists adult classes: http://www.brisbanedancecentre.com.au
There is a reccomended adult ballet teacher in Queensland here and the site in general is aimed at adult ballet dancers so has good resources: http://www.blue-diamond-dance.com/teach ... tralia.htm
And of course, Google is always a resource!