a franchise shop should charge. the shop guy (doesn't sound like it was done by a mechanic), has to justify the bulb charge, they get 11 bucks an hour so getting in Sh#t for "free" labour isn't worth it for them.
An owner or true mechanic at his/her shop, would not charge. I used to for a shop I worked at in Edmonton, and was just a garage hand. The owner just said check it and replace them at no charge for labour or bulb. Although the shop I was at specialized in Rolls, Porsche, Audi etc. So labour was 180/hour min.