Hi Pete,
I believe that all you need is the NZ registration certificate and the APC in NZ.
Then you can apply under the TTMR for registration in any Australian state or territory.
Note that Australia is devided into "states", i.e. you have to obtain the Physiotherapy registration for each state that you wish to work in (NSW, Victoria, etc.). Not a problem as such, just extra costs.
Hope this helps,
cheers,
Fyzzio