I feel like I'm getting an education in linguistics here! Good ol' Wikipedia :-). I've discovered a lot more about Australian English over the last little while.
Firstly, that unpronounced 'r' in words like 'car' makes Australian English non-rhotic. That means that we have a number of homonyms created by various mergers:
Panda-pander merger (e.g. cheetah/cheater, coda/coder, custody/custardy, ion/iron)
Father-farther merger (e.g. alms/arms, calmer/karma, spa/spar)
Pawn-porn merger (e.g. auk/orc, awe/or, caulk/cork, draw/drawer, gnaw/nor)
Caught-court merger (e.g. awe/oar, flaw/floor, haw/whore, saw/soar/sore)
Calve-carve merger (e.g. aunt/aren't, calve/carve)
Paw-poor merger (e.g. maw/moor, yaw/your/you're)
Batted-battered merger (e.g. busted/bustard, charted/chartered, humid/humoured, satin/Saturn)
The more I look into this, the more apparent it is to me that there needs to be a significant spelling component of any phonetic shorthand system. There are too many homophonous pairs (and many higher order groups!). I suspect that the system that the Phoenix authors have developed is quite adaptable on the whole to Australian English pronunciation - just occasional words with differing emphasis or pronunciation might need adjusting.
While on the homophone topic, here are two other homophone lists from Wikipedia that I may refer to later: English dialect-independent, and English dialect-dependent (not all apply, of course!).
