They are re-packaged NMBs. They've always been one of the better bearing manufacturers and far better than generic Chinese bearings. I've seen some NMBs sold on eBay or sketchy online stores, but I don't think anyone else imports them (and haven't seen them in stores for 20 years). Back in the day, German (GMN) bearings were between NMB and Bones on the hierarchy, but I haven't seen those for a long time either. I think Z (Z-roller) bought exclusive distribution rights to GMN during the late 80s and sold a version soaked in motor oil.
Just the same, you're better off sticking with Bones if you can afford them.