"Il cameriere mette l'acqua nelle bottiglie."
Translation:The waiter puts water in the bottles.
Native English Speaker here: The duolingo example is fine.
Put water in the bottles, put water in the pool, put water in the bathtub, put water in the ice trays, put water in the radiator, put water in the fish tank etc. etc. etc.
In some of the examples above you may use a faucet or hose, which we typically wouldn't describe as pouring, but that's fine too.