exmexican,
You need to look at the history of NZ and Australia. NZ was in fact governed by NSW until the states of Australia (the mainland) became a federation. NZ was invited to join and become a state of Australia (but for reasons of stupidity and financial detriment declined). The invitation is still open ended in the Australian constitution however. So NZ being part of Australian union movements does make sense, as the countries are very economically and politically related. Citizens are also free to move from country to country without residency issues.
Asia was never part of Australia and it's colonies and as such would not qualify.