Well, it's a better choice than a BA in English. However, if you don't go to an elite business school it might not do you any good. Mine never did, and there are plenty of other people in the same boat. MBAs are a glut on the market right now.
It depends upon your plan. If you want to teach English, it would be better to get a degree in education instead. What do you intend to do with your education. Getting a MBA is a good idea if that is your general direction.
I think MBA is a great choice after completing BA English. This is because it will give you an edge over those people who stopped at BA and will boost your chances of getting a job and getting promoted fast.