Another new thing learned from Flyertalk! I really must stop assuming that the information shown on BA.com has any factual base! For instance they say:

Gold Guest List Redemption Reward means one guaranteed redemption booking for a Member and up to 4 passengers travelling on the same booking, subject to availability

Member means the person who is a member of the Gold Guest List and whose name is printed on the Card;

All passengers must travel on the same booking as the Member.

So based on this I assumed that as the GGL member I could only use my Redemption Rewards when I actually traveled.

I did previously ask the GGL line if I could use one of my Redemption Rewards in combination with a 241 in my wife's name (with both of us travelling). They said that strictly speaking they were not allowed to do this, but would "see what they could do". So based on that conversation I'm even more surprised that they allow what the OP is wanting to do!