Drinking bottled water is better than the other two options most people have: drink faucet water or water from a local body of water. Everyone else just gets water filtered, bottled, or refills giant containers of it. All that water is purified, so it's a better idea instead of drinking fluoride and dirty water.
Many times bottle water is just the same as your tap water. It does not contain anything special that will improve your health. Unless, of course, your water is highly polluted. If you have something really bad in your water, it would probably improve your health to drink bottled water.