Starting later this year, I'll be flying LAX-LHR (and back) several times a year, so it seems as good a time as any to join a frequent flyer program. Now, I'll probably (unless you persuade me otherwise) be flying Air New Zealand, since they have the triple benefits of being (1) inexpensive, (2) amazing, and (3) flying LHR-HKG (which I may need to fly once a year or so, although they unfortunately don't have LAX-HKG).

However, it seems like since I don't actually live in New Zealand, or Australia, for that matter, or ever go there, I'm not sure if enrolling in ANZ's frequent flyer program is the smartest thing to do, whereas if I enrolled in a US airline's frequent flyer program, I do fly domestically within the US a few times a year.

Would it make more sense to either

(1) fly ANZ and credit the miles to an alliance program, or
(2) fly some other airline, and if so, which one?