It doesn't really matter much what it's labeled, if you like the way it sounds. The original Marshall was supposed to be a bass amp, from what I've read, as was the Fender Bassman amp, but guitarists loved them, and the rest is history. So plug in, turn on, and make some noise. See what you think.
The one exception to all of that is one shouldn't, as a general rule, use guitar speakers for bass. That can pretty easily result in blown speakers. Guitar amps for bass, no problem, but not so much the speakers.
