Yes, your eyes do deceive you. Madonna has never released a cover of 'The Wheels On The Bus'. Mad Donna, on the other hand, has.
Who exactly was behind Mad Donna is unclear (there's some nonsense on their background here), yet whoever it was, they had an inspired idea: to get a Madonna impersonator to sing a nursery rhyme over 'Ray Of Light'. It went a little like this:
It was released in April 2002 (by comedy dance label All Around The World, no less) - either around the height of the whole bootleg 'thing', or three years after the point 'Ray Of Light' was still ripe for parody, depending on your generosity. Regardless, it was a time when any song with just a modicum of promotion could reach the Top 40, and 'The Wheels On The Bus' duly went in like a bullet at Number 17.
This prompted a rather bizarre Top Of The Pops performance. The gimmick now had to be represented physically, and how could that be easily achieved? With a 'band' made up of four Madonna lookalikes, performing to a largely uninterested and mainly baffled crowd.
Following that the track managed another two weeks in the lower reaches of the Top 40, a fortnight that, unsurprisingly, represented the last the world was to see of Mad Donna. If you're hankering for more, there was a b-side, 'Hush Little Baby', set to 'Don't Tell Me'.
It's not as good. Anyway, as you might have noticed 'The Wheels On The Bus' didn't exactly set the wheels (!) of a lullabye-set-to-not-quite-contemporary-pop-hits fad in motion (although another Madonna appropriation, Mad'House's 'Like A Prayer', did go on to be a bigger hit later in the year). Whether that's a good or bad thing is up to you (it's a good thing), but legacy or no legacy it did get a 3/10 from Drowned In Sound, and that's two points more than Calvin Harris got for his debut album, so it's swings and roundabouts.