If iPhone for an ambulance can you chose which hospital to go to?

Yes, with a few caveats. You may choose which hospital you want to go to as long as they are about the same distance away. If your preferred hospital is substantially farther away than the facility of similar care level, you may have to go to the closer of the two. If you do go to the more distant hospital, insurance may not cover the trip, or make you pay the difference.