You can make the first piece of the booking online (in most cases).
Any subsequent change/addition/amendment must be over the phone, or by online chat. I you give booking reference, name, date and destination of first flight etc identification questions, you should be able to do it via chat. But WP might be able to have more 'access' to especially QF award seats than you have doing it yourself. Partner airlines shouldnt be any different
Interesting. So if the first flight is booked for me by my WP family member, would I be able to make the amendments or would it have to be my WP family member?