You can not bring the grounded conductor from the 480 volt supply and connect it to the bonded XO terminal of the transformer. This would be a rebonding of the 480 volt grounded conductor and is a code violation. You must bring an equipment grounding conductor from the 480 volt source to the transformer and this conductor will be indirectly connected to the secondary grounded conductor via the main bonding jumper.
Don(resqcapt19)
