You are right about bears (at least black bears) being more interested in chicken food than chickens (see post # 21 above). So be sure to store your food in a secure location and preferably separate from the chickens themselves.
But if a particular bear develops a "taste" for chickens as a food item, it can do a lot of damage to your facilities and your poultry. Your facility sounds pretty secure for most predators, but do give some attention to preventing going under as well as over. I had a chicken wire apron in the case above which worked for racoons for over a decade. But now I have a WSW apron all around.