Don't you have anything more specific? I had not heard that Reagan travelled with Bogart. In fact, I had heard that opposite...that Reagan cooperated with Congress despite the Bogart and Bacalls protest.
During Bogart's trip he came to realize that he was being used and he afterward protested Communist publications using his name. I will need to find my source on that, but I've read it in several places--should be online, or if not, in Bogart biographies or books on the Hollywood Ten.