Oh, gosh, this is a program where no one before seems to have ever asked about that. (Most people don't have an overload of WynhdamRewards points to use some of them for other people, and most people don't consider most of WR's brands to be worth giving as "gift" stays to someone else.)
So while people have asked about merging points from different accounts before (and it turns out that it can't be done), I can't recall (or find) any person who's asked before about booking with WyndhamReward points for someone else.
At some hotel programs, you do that by calling them up on the phone. At some other hotel programs, you do that by putting the other person's name as an "additional guest", and then explaining that this "additional guest" will be checking in (by themselves) first.
But I don't know if either of these approaches (or anything else) works at WR.
It's not a program where people tend to have tons of points and thus want to gift stays. And it not a program with lots of nice properties that people would want to choose for gift stays. (It's not that there are no nice properties, but the bulk of WR"s properties is Days Inn and Super 8 and Travelodge, and who would want to give gift stays for those???)