What should I do, lumineers vs bonding?

I would suggest that you have orthodontics to close the spaces now that your adult canines have fully erupted. This can most likely be done with Invisalign, but of course an orthodontist should make that final decision. For your age, this would be the best way to go. Any form of veneers at this time would be overkill, and composite bonding is definitely more conservative, however would require maintenance and need to be redone several times becuase of staining and chipping that will occur over the course of time with composite.

Seeing the photo of your teeth and the gaps, you could be treated with either. But since you are sixteen years old, most cosmetic dentists will recommend direct composite bonding, and replace them later with porcelain veneers when your are an adult.Since your teeth look healthy and straight, and have small gaps, your dentist could use a number of porcelain veneer techniques that can allow the veneers to be thin. Lumineers are just one such technique, but Lumineers are most often done with feldspathic porcelain, which is no longer considered the state of the art material by most cosmetic dentists. A much improved material now coming into great popularity is EMax porcelain for porcelain veneers. They can be made as thin as Lumineers, but much stronger, and thus will most likely last longer than the old style feldspathic veneers.

It is very possible to close your gaps with orthodontics. If you are hesitant to get braces again, Invisalign would be a great option. Veneers or bonding would work well but Invisalign would be the least invasive and probably least expensive approach.