Every FF plan has its own rules as to mileage earning classes on its own and other
alliance members flights. You have to check the rules of the airline you which to accrue
to, they will show which classes you earn miles on, and whether they are full miles
or a percentage.

A quick glance at Mileage Plus web site shows:

Mileage Accrual Chart
International Flights (including Tahiti)
Eligible Air New Zealand fare classes MileagePlus Premier qualification
Class of service Purchased fare class Base miles* Premier qualifying miles Premier qualifying segments
Business C, D, J, Z 125% 150% 1.5
Pacific Premium Economy U, E, O, A 100% 150% 1.5
Full Fare Economy Y, B 100% 150% 1.5
Economy H, M, Q, V, W, T 100% 100% 1
All other fare classes do not accrue mileage. United Airlines® and Air New Zealand reserve the right to change the eligible fare classes at any time without notice.