I appreciate the feedback from my fellow FT'ers, but my main point wasn't about the resolution of the problem, since I resolved it myself by flying Southwest to LA to catch the LAX-AKL flight. The issue was the lack of communication between Air NZ, UA and me:

1) Last summer, how did NZ manage to rebook me on a UA flight to LAX that would obviously arrive after their departure to AKL? And why wasn't I notified about the schedule change?

2) On the day of departure and with three hours to go until scheduled flight time, the UA flight was already showing delays of 2-1/2 hours. Why couldn't UA or NZ have notified me when they first became aware of a problem that would clearly cause a misconnection? (Answer: according to the agent at NZ at the time, their system didn't even show a delay on the UA flight.)

My point is that I had a naive understanding about their alliance partnership and what it means in practice. Apparently it's just a mechanism for code-sharing and frequent flier program benefits, and that's where it ends, despite the Star Alliance hyperbole.

And while some may opine that they would have opted for the option to fly Economy Minus on UA, I wonder about that. If you had paid thousands of dollars to fly Premium Economy on NZ and instead would get stuck in middle seats in the back of a dated UA 747 for 14 hours, would you be satisfied? (Especially since neither UA or NZ wanted to discuss compensation for the inconvenience while the problem was occurring.) Try collecting the fare difference after the fact? Right.

Anyway, I've learned my lesson. It's a shame since I think Air NZ has a terrific product and incredibly attentive service once you're on their aircraft. Still, their reservation agents and ground staff could learn a few things about customer service. Next time I'll either board their metal at SFO or fly Qantas!