The cables are glanded with Hawke Cable Glands and the gland is made up to a Crouse Hinds STXG Myers Hub. The hub is listed for grounding, question is, is a bond wire required to meet the listing and if so what woud be the reference for sizing the bond.
Here's an image off Hawkes website of their industrial gland...
I am wondering why it is not directly connecting to the enclosure. Myers Hubs are typically used for conduit terminations to enclosures.
Whether or not the hub itself requires a bonding jumper is subject to the details of connection to the enclosure coupled with the requirements of 250.97, its permissions to deviate under the exception, and 250.100 (which essentially nullifies 250.97 Exception). Without you providing those details, I cannot say whether or not a bonding jumper is required. What I can say is, if in doubt, add the jumper! ...and as I recall it has to be sized the same as the EGC.