Can I do dental bonding? Is my gap too big? (Photo)

You have a beautiful expressive face and your gap can be restored with bonding.   If you just make the gap smaller it won't make the teeth look as wide.  Bonding a diastema is not that expensive but each doctor will charge differently so you should discuss fees upfront.

For your case I recommend Porcelain veneers, due to your smile,i recommend at least 10 uppers. That way you will change completely the shape , size and color of your teeth , even close that gap, they will look more nice and even, this procedure can be done within just a couple of days, with porcelain veneers

From the photo, it certainly looks like either composite bonding of the 2 front teeth or porcelain/composite veneers on the 2 front teeth would work well for you. The bonding is less expensive than the porcelain but may not last as long(may tend to pick up staining and discolor somewhat over time) but it is also more conservative in that no tooth structure would need to be removed. Porcelain veneers may also be able  to be done very conservatively. Find a  dentist who has done a lot of these and see photos of what they have done. The cost will depend upon your area ,of course, but the porcelain is usually twice the cost of the bonding.