I live in the Northeastern US and have been through 1 winter. I wash the truck every other week and have a tonneau cover. I don't recall damaging the bolt and noticed it is rusting.




2016 XLT - Rusty bolt near tailgate


Wondering if I can ignore or if this will become a bigger issue with the aluminum parts nearby.

 

You should go back to the dealership and have it replaced under warranty.