Assuming metalic raceways, bonding at both locations is not just a misunderstanding of the NEC, it is a violation of 250.30(A)(1)
(1) System Bonding Jumper An unspliced system bonding jumper in compliance with 250.28(A) through (D) that is sized based on the derived phase conductors shall be used to connect the equipment grounding conductors of the separately derived system to the grounded conductor. This connection shall be made at any single point on the separately derived system from the source to the first system disconnecting means or overcurrent device, or it shall be made at the source of a separately derived system that has no disconnecting means or overcurrent devices.
Exception No 2 to this article section would allow bonding at both locations if there were no parallel paths created in doing so but, this would mean a wooden structure with NM cable or NM raceways.
Roger
