I wasn't aware that both stations didn't play "Taxi". "Rhapsody In The Rain" by Lou Christie referred to "making Love in the Rain". They played that song. How long was "Bohemian Rhapsody?" They played that and it was pretty long. I don't know why they didn't play "Taxi" it was a very good song.
I also don't recall "Taxi" being banned on either station. But I was living downstate when that song came out. It definitely was in regular rotation on KSTT and WQUA in the Quad cities where I was. And the jocks were also playing it on WHBF, my gig at the time (but not as a jock). At least at night (we basically followed the Billboard AC chart). I also remember it being on WIRL. Hard to believe what was OK in Davenport, Rock Island, Moline, and Peoria was "too hot to handle" for Chicago.