This is not the first time I've featured the Peregrinator's Club, but the other time was on Earth-12 and in the future. This is on Earth-0 and in the present. And this is actually the TRUE first appearance, so it's more important.
The Peregrinator's Club is a men's club where the Gotham Police Department held a party for Commissioner Gordon in the episode "Joker's Favor" (1992), which is also notable for featuring the debut of Harley Quinn.
That episode was written by Paul Dini, and about fifteen years later, Dini started a run on Detective Comics. So in his very first issue - Detective Comics #821 (July 2006) - he featured the Peregrinator's Club as a setting.