You're mixing Alaska and Chase UR, which don't transfer to each other at all. This is probably best asked somewhere else, but Alaska partners fly to Australia. A transcontinental nets about 4.5k miles roundtrip, which is a drop in the bucket for an Australia mileage redemption. You need I think about 40k each way so that's 160k miles for 2 rt. If you stick with Chase only and disregard Alaska, you can transfer to United, about the same mileage required. Or you can open BoA Alaska a couple times which gets you 25k each time and do one way in Alaska partners and one way with Chase partners, probably United best.