Like anything where you have to deal with government agencies it is not straight forward or sensible - ha ha!!! According to the government website there is no six month test (so either they have changed the rules since Spockey applied or the test still applies and they just don't bother to tell you about it until after you apply). I am actually a lawyer but I don't practice in this area of law so I am in the same boat as anyone else trying to work out what the entitlements are - i.e. confused but hopefull!!
According to the test on the government website, a claimant meets the Australian residency requirements if:
1. "the claimant has legal residence status" - i.e. has the right to reside in Aust as an Aussie passport holder or on the types of visa listed,
2. "is living in Australia on a permanent basis" -I think that given the 3 year temporary absence allowed (i.e. "eligibility may be maintained during a temporary absence from Australia for up to three years") this has to be interpreted as "intends" to live in Australia on a permanent basis. Otherwise why say that people who live outside of Australia for up to 3 years are still eligible??
So an expat, for the purposes of these specific rules, could claim that they intend to live in Australia on a permanent basis and that Australia is indeed their permanent home if they haven't been living out of Aust for 3 years. Of course this has to be a true reflection of the facts - i.e. you couldn't claim it if you intended to live in HK permanently.
Anyway, baby number 2 is due in 3 weeks so I'll apply as soon as I can after the birth and let you know how I go. Baby number 1 was born in Australia so there were no issues with obtaining the baby bonus for that one.