Not as easy as just sitting AA..
Yes it is, little thing called the TTMRA (Trans Tasman Mutual Recognition Agreement).
http://www.casa.gov.au/ame/TTMRA.htm
The general Syllabus is on the CASA site but I couldn't see on for AA.
When I did mine years ago (while the final legislation was going thru for the TTMRA) the company I worked for arranged for our training engineer to run us thru it (like a couple of guys used to do for the written and oral in NZ)