How does one work out award pricing for an AAadvantage booking from Australia to USA?

Is it still possible to book an Aadvantage award flight in J from Australia to USA for 60K miles with Cathay or JAL on one booking?
Someone told me you now have to make two separate bookings. Australia to Asia, Asia to USA.
Usually no availability with QF or AA.

Should be fine to make one booking with a connection in between. I believe stop overs are more troublesome however.

At present, MEL-HKG-ORD in J requires 110K Aadvantage miles with CX and SYD-HND-JFK requires 100K miles with JAL.
Aadvantage mileage reward chart shows South Pacificto USA should require 80K miles.
Can somebody explain this.

I believe they count as separate segments when calculating miles required. So for your itinerary, it would actually be South Pacific → Asia Region 1 → Contiguous US states or South Pacific → Asia Region 2 → US States. They are either 40K+60K points or 40K+70K respectively so that’s why it would be 100 or 110K for your itineraries.

Hope that helps.