VFR on Top...Bravo clearance?

[Rexflyt]

OK, I have a question that I thought I was sure of until last week. I haven't referred to the FAR/AIM yet, I thought I would just ask here first.

I fly into Bravo airspace nightly for work and I use On Top when I can to save some time and as I understand it since I am on an IFR clearance I don't need Bravo clearance. However, last week as I was getting close to the airspace I notified approach that I was beginning my descent and they acknowledged with a cleared to descend through class Bravo. I thought OK that is odd. So the next night as I approached the airspace I thought OK I'll play the game and told them I was beginning my descent with a request to descend through their Bravo. The controller acknowledged my descent with a "no need for Bravo clearance since I'm on top". That is what I originally thought but there seems to be some confusion some where.

 

[genot]

You don't need one. Understand in the terminal environment we may or may not have your strip, just whats on the data block. I can't count how many times a tower's release request has ended with me saying "where is he going?" "Whats his type?" or having absolutely no clue where the airplane is landing. If I see you at a VFR altitude, your code could very well be vague and either IFR or VFR. I'll probably assume you're VFR an thus issue the clearance through bravo.

OTOH the controller just may not have known better.