Originally Posted by TeflonMan

Isn't there also a requirement for your guest to be on the same flight as you?

A while ago, I tried to help out a dad trying to bring both his young children into the Galleries lounge at LHR. The lounge lady initially declined his request on the grounds that he could only guest in one person and the lounge was very busy. When I offered to guest in the other child, she said that would not normally be possible as the child was not on the same flight as I. She did let both kids in on that occasion, but said it was an exception.