Guppies CAN live in a bowl or small tank, as long as there is enough oxygen, and heat. A bowl with an airstone and a heater will keep a guppy alive, but it isn't ideal. Sadly, before I knew any better, I was keeping my 2 guppies in a 2.5 gallon, unheated, unfiltered, un anything-ed tank. They lived for quite some time like this. So my guess is guppies CAN survive like this, but theur lives will be shortened. Also, my neighbors keep a huge goldfish bowl (5 gallons about) in their living room with guppies in it, and they have surived for a while. Once again, it is frowned apon, but to answer your question, they CAN live in a bowl.
Edit: also, one male will get kind of lonely.