Wirelessly posted (Mozilla/5.0 (BlackBerry; U; BlackBerry 9930; en-US) AppleWebKit/534.11+ (KHTML, like Gecko) Version/7.1.0.755 Mobile Safari/534.11+)
Maybe, maybe not.
They probably are fully flexible but there is no guarantee. If you really need to know call and ask an agent to check the specific fare rules.