Yes, this is a bit of a cheat since Superman isn't in it, even though he is mentioned. While Batman and Robin both appeared on the Superman animated series and Superman even traveled to Gotham City, Supes did not appear on either of the 90's Batman animated incarnations, but Supergirl did. In Girls' Nite Out, the Girl Wonder and Girl of Steel teamed up against Poison Ivy, Harley Quinn, and Superman series original Livewire.
Its also worth mentioning that when Superman: The Animated Series and The New Batman Adventures aired together as The New Batman Superman Adventures, the shows received an incredible new animated intro with a great theme. Those were the days!
Check back next week for another chapter in The Super History of Superman.