No fish should ever be kept in a bowl or any other unfiltered container, including Bettas. Adding the fish to a proper aquarium would be a very good idea however ensure that you don't have any other long-finned species such as guppies or other anabantoids, the same applies to fin-nippers such as certain barbs and tetras, as well as aggressive cichlids.
Contrary to popular belief, Bettas can be kept with other species, so long as they are suitable.
Contrary to popular belief, Bettas can be kept with other species, so long as they are suitable.