When Columbo returned to the air in 1989 on ABC, it was further established that Lt. Columbo and his wife were still happily married, and the existence of the series Mrs. Columbo was effectively ignored. However, in one episode, in an apparent put down of the show bearing his name, Columbo commented, "A woman's been going around saying she's my wife, but that isn't her..."
There were a couple of episodes included with my DVD set. Not terrible, but certainly not up to Columbo standards.
Have you watched them?
Here's all I've watched from the following Columbo DVDs:
Season 3: Bonus Episode: Mrs. Columbo "Murder is a Parlor Game"
Season 4: Bonus Episode: Mrs. Columbo "A Riddle for Puppets"
I think that Wikipedia is incorrect here (hard to believe, I know :) ). The quote it references is from The Columbo Phile - Levinson and Link mention that they WANTED to say something like that, but it never made it into an episode.
There's a MAD Magazine spoof of "Star Trek: Voyager" in which behind Captain Janeway there can be seen a picture of Falk as Columbo with the inscription, "Take my wife, please!"