[timv]

The ABS has been providing shape files of their geographies for quite a while.

While they're not a perfect match for the official administrative boundaries, they're good enough for many use cases.

Amoung other things, they provide polygons for suburbs, LGAs, and postcodes.

[MapMaker]

FYI these "Non ABS" geographies form part of the Australian Staistical Geography Standard and the 2016 version will be formed by aggregates of Mesh Blocks. The alignment between ABS versions and the official ones will be much much closer.