The AUS version has only recently appeared on MyArchicad but I would have thought the NZ version wouldn't be far behind.
Look closely in MyArchicad - there will be a single button at the top of the list of what you have already downloaded that says something like "New Version".
I can't show you a screen shot as I have already downloaded 18 so that button is gone now for me.
If it is not there then maybe the NZ version has not been released yet.
One of our NZ talkers may be able to enlighten us on that?