I don't know but no matter what I would bring the baby's regular shampoo. Don't want to risk a rash or other reaction. If you need enough grocery type items and diaper you can order them and have then sent to your resort!
I would just bring some from home. Cheaper, plus you know for sure that you have it. i.e. why run the risk of the resort shop being out of it? You might even check in a place like Target or Walmart...I remember picking up sample sizes way back when that were perfect for travel.
I'll join the "bring you own" camp. Our grocery store has a travel size section of all the usual stuff and even has a J&J small bottle of tearless shampoo there. I bought one and pack it each trip. I have filled it with other shampoo since it is a few years old and the family tends to "borrow" my supply. As you are shampooing an infant, a small bottle should last the entire trip.