I've been meaning to do this for a while, but I just did today. I called General Mills which makes Gold Medal flour to ask if it was bromated. She said none of the Gold Medal flours are bromated.
The Great Value flour didn't have a phone number, but it is Walmart's brand, so I suppose I'd have to call them to ask about their flour. The only thing is, that I don't know if Great Value sells unbleached, and I would never have bought the bleached myself, so hopefully I'll never have that brand again, which makes it kind of academic.