What are you plans with the ff miles earned?
Look at the partners of NZ & VA (eg. Virgin Atlantic, Delta). You may be better to credit to a partner ffp.
Treat flight separately
Air NZ is a &**& of a ffp. Hard to find any ffp that is worse. More so if you do not live in NZ or take a lot of NZ flights.
http://www.flyertalk.com/forum/infor...help-here.html