I have bonding on my front teeth from when I was 17 years old due to a genetic flaw that caused my permanent teeth to grow in with horizontal "chasms" across my teeth and weakened enamel; I never had a chance at naturally beautiful teeth. The bonding was done to fill the pitting and protect my teeth. Added benefit for me was that for the first time in my life I had beautiful, normal looking teeth and felt like I could smile ... my normal smile was a Mona Lisa, not showing teeth. The oil pulling hasn't harmed it at all. That bonding was technically supposed to be replaced after 9 years ... I'm 40 now, so it's lasted 23 years so far. I'll probably get it replaced in a few years (when I can afford it again), as the plastic has worn at the edges some over the years. But I can say for sure in my case that the oil pulling has NOT damaged the bonding, and has actually nicely brightened and cleaned.
Also, back when I was getting the bonding done all those years ago, I did have some of the layers of plastic come off on a few teeth, but the dentist fixed those at his cost ... he hadn't gotten the plastic to bond properly in those cases. So IF it happens to you within a short time of having the original work done, I would think your dentist should fix.