I can't imagine how this is enforced. Clipper cards and cash will get you on any bus without any sort of check to see if you're allowed. There is probably a lot of overlap of people who get banned the people who skip gates and fares.
If Walmart and Target can manage facial recognition for shoplifting, I'd imagine it's at least possible to do with a bus system.
If Walmart and Target can manage facial recognition for shoplifting, I'd imagine it's at least possible to do with a bus system.