Frank Wayne is the guy who revamped TPIR for the '70s. He was originally a writer on, then producer of, Beat the Clock. I don't think he had any connection to the New York version of TPIR, but Canadian BTC was cancelled in the late '60s I think (help me out here, Zach) so his incentive was that it would give him a show to E.P. He later hired his son as a producer. His son held that position until just recently and now has a lawsuit pending against him.
The only person on staff for the specific purpose of creating game ideas was Steve Ryan. All other game ideas were originated by Goodson's "inner circle" of producers and directors or by people outside the "inner circle" who brought ideas to producers. Even Steve Ryan had other assignments besides creating game ideas. When I was there he spent most of his time writing P+ puzzles.
The OP asked about compensation. While people generally don't go around discussing their salary packages with others, one of them did with me. Without divulging their identity, this person who was not a producer created a show which went to air. They received $750 per week for the position they held on the show's staff plus $750 per week as a sort of royalty payment. $1,500 per week was handsome compensation at the time but you also have to remember that the emcee of that show was probably receiving roughly triple that amount. The announcer of the show was probably receiving an amount comparable to $1,500 per week and the producer much more.
If you were a producer and you came up with a new version of Password as Bobby Sherman did or, say, Gambit as Bob Noah did at Heatter-Quigley, you now have a show to produce and you got paid for it. With Match Game teetering on the brink after CBS cancelled it, Bobby and Ira had plenty of incentive to cultivate new ideas. There was also the factor that people who developed games made themselves more valuable to the company.
Re Xmas bonuses: I've been told that Frank Wayne and Paul Alter used to receive $100,000 Xmas bonuses. They're the only ones I can vouch for. Everyone in the company received some kind of Xmas bonus but I don't know the amounts of anyone else's. Ironically Frank Wayne used to grumble, well he used to grumble about a lot of things and right to Goodson's face, but he used to grumble that Goodson had discontinued company profit sharing. I seem to recall hearing that profit sharing was instituted for the likes of John Daly and Frank Heller and there was supposedly some sort of tax benefit for them back in the days before 401(k)s.