In general, in my experience, businesses do not approach you for bringing in food or drinks for infants.
This has included bottle breast milk, juice, water, crackers, treats, fruit snacks, meal/snack squeeze pouches, and much more.
My rule of thumb is that if my child is not old enough to be charged admission, then the rules prohibiting outside food and drink don't apply. However, even for my toddler we still make sure to carry certain snacks on hand in the diaper bag to ensure his dietary requirements are met. We can't guarantee vendors will have the proper food, or that we'll be able to get it soon enough to sate him. For instance, when we visited the zoo, it could be a long walk between water fountains.
You can check with the business beforehand, but I'd rather ask forgiveness than permission in this case. I find it very unlikely that most employees will approach you for feeding your young child, even if their business policy says otherwise. I think reasonable people will recognize that it's not something worth confronting a customer about. So, I would not plan around the exception.