Yes, CX does not fly any F to Australia. So, you can either redeem an F award to Australia and get F LAX-HKG and J HKG-SYD or redeem a J award to get J all the way and save a few miles.

This works from any CX North American gateway. If you are using CX from YVR, SFO or LAX, AS will also include an AS flight to/from your CX flight provided award space is available.

If you do spring for F, CX still flies one 747 to/from SFO. I find the cabin in the 747 nicer than the 777. It will got to 1x a week starting in September. Yes, 1st world problem.