Just a quick follow up.
I was able to add the other passenger on my friends and family list. Unfortunately, that took too long and the reward flights were gone. I then signed up for AwardNexus and a reward on the return flight become available a few days later. I was able to upgrade us both to CW from WT+ for 30K points and £84 from PVG to LHR.
Hoping that an outbound reward becomes available.
Thanks for everyones help!^