How long does it take a vaginal tear to heal after delivery?

It depends. Most tears should heal within two to three weeks at the most. Topical Bacitracin (not neosporin) with a pad should be changed two to three times daily, and at least a daily bath or shower. It should heal without any problems but it might be sore for a few weeks to months so be careful with intercourse and bicycles, spin classes, etc.