So what you’ve actually done is taught him that if he makes enough of a fuss for long enough, he will get his own way.
In reality, as the adult in this situation, it’s up to you to make the decision. Be very clear though, your child will not dehydrate because you won’t give them a bottle anymore. Make sure they have lots of ‘wet’ food - cereal, ice pops, juicy fruit, gravy etc.