Just an update if anyone's interested. I didn't get the option to upgrade on the outward sector but I did on the return.
On the "manage my booking" part of the website, about 10 days before the flight I was offered an upgrade from WT to WT+ for $940 (flight was booked and paid for via an agent in the US, hence the pricing in dollars).
I thought this was too much extra to go WT+ so I left it.
Then 5 days prior to travel it changed to where I was given the option to upgrade from WT to Club world but as this was $1760, I also gave it a miss.
Then 2 days before my return flight, I checked the website again and the upgrade to Club had dropped from $1760 to $840, a deal that I decided to take.