Well, most people see bear as dumb animals, but they're actually quite smart. If 'your' bear can find any easier food to get, your coop just might be on it's list under the Too Much Trouble To Bother category.
Yeah, your yard is a no shoot zone for sure, and I agree a hot fence strand wrapped around the building and pen will go a long ways to discourage them... people in Alaska use them with much (though not total of course) success. I had a friend up there who had a barn with goats, and she figures that's all that saved them a few times. One or two zaps on the nose makes them decide it's better to avoid the place. They tend to learn fast and well though teenage bears are more reckless, and RestlessCrow, a mom with cubs is both more dangerous AND more cautious if that makes any sense. So a hot wire with cubs around and the mom will take the cubs far away as long as she's not starving.