The labels are Water Resistant
The adhesive on the label will adhere to new bottles of shampoo or other such products and will stay on with normal use over the life of the bottle. The ink will not bleed from being wet.
However, if a label is placed on a bottle that has already been in use in the shower, the label will not adhere properly. A possible solution is to wash the bottle in soap and hot water and rinse and dry it thoroughly.
How successfully a label stays on an already-in-use bottle will depend entirely on the bottle being completely clean and dry without any residual soap residue.