Ask the dentist. Ask the dentist who did the bonding.
No. Bonded composites are not affected by whitening. The best way to change the shade is to replace the restorations. You can also add another layer of a whiter material, however this is not as effective.
No. Natural teeth respond to the whitening agents, but dental materials (porcelain or tooth-colored bonding materials) will not. Often, users of otc whiteners get the unpleasant surprise of mismatched teeth for that reason. Consult your dentist about a plan to whiten your own teeth and then poosibly replace the old bonding material with more of the same or porcelain veneers.