I would never book flights directly through the ANZ rewards program - you'll get much better value by transferring them to an airline program. Velocity or Singapore Airlines would have to be the obvious options, and if your goal is flights to the USA then Velocity would probably have an edge. As already mentioned, wait for a transfer bonus (these are usually offered twice per year and add 15% of value to your points).
You'll need to save up a bit more though (or take advantage of a few sign-up bonuses!) to get enough points for return business class flights to the States. 100K ANZ points = 50K Velocity points. That redemption would cost almost 200K Velocity points.