Can dental bonding add thickness to teeth thinned really bad by acid? Also can they whiten yellow teeth that can't be whitened?

It's more than soda that's thinning your teeth, it's your bite.  Your top front teeth are probably very short as well. You need a comprehensive workup by an extremely qualified dentist who takes temporomandibular joint problems into account.please don't think that simply putting veneers or composite on your front teeth is going to solve any problems that are going on with your teeth in general.

Bonding can thicken and whiten teeth.  However I am assuming that your acid thinned teeth are not decayed and have sufficient enamel to bond to.  You can bond to the inner layer called dentin but it is not as strong. In regards to orthodontic treatment, depending on whether your dentist wants to band or just place bonded brackets....bonding may not be needed until you complete the case and the bands or brackets are removed. Last possible alternative (depending on your case) you might be a candidate for invisible ortho such as Invisalign or Clear Correct, in which case the bonding can be done and adjusted as the treatment proceeds.