when a person is on bail are they allowed to leave the country

As a general matter, a person on bail is often not allowed to leave the state, much less the country. The judge in each case will make a determination as to whether the conditions of bail will include a restriction on leaving the state.  It is standard that a judge will not allow an individual who is out on bail to leave the country.  Furthermore, if the judge believe that you might make an attempt to leave the country, he will take your passport. In short, if you are out on bail, you travel plans should be domestic, and probably in-state.