Data Communication Rack Bonding

I've attached a rough sketch of a communications riser for a school design Im working on. I'm questioning if the bonding layout for my racks is appropriate. Specifically if its required to bond each rack to its respective building steel, of if I should keep a isolated ground back to the main ground bar in the main communications room. I've read that if you dont the you can create a potential difference if something on the building ground shorts.