I assume that what you are talking about doing is making a pot of soup, ladling it into some bowls, sprinkling some cheese on top, putting the bowls on a baking/cookie sheet and then sliding it into a pre-heated oven for 2-3 minutes to melt the cheese?
If the bowl is plastic, glass or thin china - it would probably (but no guarantee) be safe if the oven temp was not over 150ºF - BUT, definately NOT under the broiler.
If your bowl is a glazed pottery type material - sure, 350ºF should be fine. Under the boiler would also probably work if you kept the bowl 6-8 inches away.
Of course - to be totally safe ... you could use the microwave to melt the cheese.
It's really hard to give you a more definitive answer not knowing any more than you have told us about "the bowl".