The current United International Route map doesn't show them as flying to New Zealand, so that's out. The "nearest" options for picking up a United plane are Australia or Hawaii.
Using the United award travel calculator and the current award chart, you're out of luck on heading to the states from New Zealand, you just don't have enough points for even a one-way, by almost an order of magnitude...
Hawaii to the mainland US is 22,500 miles in discounted economy, so if you got yourself to Hawaii somehow, you could carry on to the states, but not be able to get back! So, that's out
Two flights within the Australia / New Zealand area are 17,500 miles on-way at the discounted level, 35,000 return. Other near-ish options are New Zealand to Hawaii for 35,000 miles discounted one-way, or New Zealand to some of the pacific islands (Oceania) for 22,500 discounted one way.
Frankly, to do anything interesting, you're going to have to buy some miles / transfer some miles in from a supported other program (eg SPG, Amex MR). With not too many more miles for you, and hoping for economy availability, you could have a nice trip over the Tasman Sea to anywhere in Australia. With some more miles for both of you, some of the nearby pacific islands are an option. With double the points for your wife, and more than that for you, a trip to Hawaii could be done. With anything where you need to buy miles though, check the cost of "taxes and fees" - award flights aren't free! Only go for it if the cash ticket cost is less than the cost of taxes and fees, plus the cost of buying the extra miles.