I don't think it's intended to be a Japanese pun at all considering how the film seems to take pains to remove anything remotely "Japanese" about the setting and characters to make it look like a badass Hollywood fantasy action movie.
There seems to be an izakaya in Insomnia that Nyx and his gang will visit, but yeah, Tokyo!Insomnia is dead.
This was said during the recent CGWorld Making-of stream:
It's interesting to hear that Insomnia's westernized design is seemingly actually the result of Japanese fans complaining about the city's similiarity to Tokyo. According to one of the art directors, the goal was to create something that would feel distinct for Western and Japanese audiences.