I always get the different names of that theatre confused. I don't think the book is specific about any of the other contracts, but I would assume they were all Broadway contracts. (I got the book as an e-book, which was great to take along to read on a cruise but not good to be able to shuffle though pages for something specific.) I had forgot about Man of La Mancha.
Yesterday, after posting, I looked to see what I could find in Variety about Grease and the Tonys. Variety simply said that the show was on Broadway contracts, so I imagine that means everyone, not just the actors.