Originally Posted by
sbm12
Awards cannot be booked on codeshare partners as a general rule. This definitely applies in the case of United points on the LAX-PPT flight which is not operated on NZ metal.
But the OP wishes to earn miles, not redeem them (other than for an upgrade, if possible). I have no idea whether this is possible on the NZ codeshare LAX-PPT operated by TN, but my gut feeling is it isn't. Maybe if the thread hadn't been moved from the UA forum somebody would have been able to answer.