Just in case it isn't clear from the other replies, a bull license is always a list A tag, but a list A tag does not necessarily have to be a Bull tag and can be a cow tag depending on the type of license. So the short of it is that you can effectively only have one Bull tag in any given season with a few very small exceptions. If you want another tag, you can find a list b license which are all antlerless tags. Conversely you could start archery with the OTC Antlerless license which is a list B tag and then pick up any other license that you want.