This is just to notify geeks out there that this data exists. I'm sure this will be of real interest to someone out there, perhaps someone building a mySociety for Australia.
The federal parliament's parliamentary library just published a paper called Postcodes in electoral divisions, and describes the postcodes in federal electoral divisions and the percentage of that postcode that is within a division. Very handy stuff, for a very narrow group of users.
The copyright statement at the end is probably boilerplate, because it certainly doesn't match up with the publication of such a useful dataset, paid for by the public.
PS: It's well worth signing up to library feeds as there's a wealth of useful stuff issued by this organisation. I've particularly appreciated the bills digests, which explain the purpose of bills before parliament in quite neutral language.