I've noticed that my partner's Airpoints account looks different than mine with a few different features. I assume this is because she has a NZ address listed whereas I have a US address. At the moment, which address is technically 'primary' for me is a bit ambiguous, so I wondered if there is there any benefit to using one over the other?

For instance I don't have a OneSmart card because this doesn't seem to be offered to US customers ... but I'm not sure that I would use it anyway, because a good US credit card pays a flat 2% cash back, has a good exchange rate w/ NZD, and no foreign transaction fees. But maybe there are other benefits that I don't know about, especially once I hit Elite in a few weeks?

Thanks in advance for any advice.