Also some VIP rooms have gone dry post-pandemic and have nothing in there, no food no beverage, and at those resorts it's just easier and more convenient to cart in your own water. We bring our own water because some of the resorts hand out water freely in their VIP and some do not. While these bottles aren't exactly visible in the insulated bags we put them in, also sometimes we bring a 2.5 gallon container of spring water for the tea we make in the room in our stainless steel boiler, and it's obvious what that is and no one has ever stopped us from bringing the water upstairs.
No one has ever objected including at the casinos you mention above. The bellmen carry all of our belongings, except as noted at the one resort.
When we arrive in Vegas we are typically carrying dozens of bottles of health drinks that are hard to get inside the hotels. The only rule we saw enforced was at one of the Vegas resorts we stayed at Oct/Nov 2020, the bellmen would not cart any food or drink - we had to carry these ourselves, and this was a Covid era rule, nothing to do with any policy against bringing in food and drink.
