I have white spots on my teeth after dental bonding. Why did this happen and can it be fixed?

There may be several causes for the white spots on your teeth but from your description the seem to be developmental in nature, meaning they occurred when your adult teeth were forming. It's possible you may have had fevers or ear infections when you were very young and that is when these teeth were beginning to form. Once the fevers etc. stopped the teeth continued to form without spots. Spots like these often become more noticeable when teeth become dehydrated. Depending on how obvious they are you may need to have veneers done to correct the situation. I would recommend a consult with a cosmetic dentist to discuss your treatment options.