If you major in either banking or finances, of course, you will be able to narrow your focus on a particular area in the fiance world. The finance and banking worlds are extremely broad. In fact, the banking world alone is so broad that you will have to be narrowing your focus down.
With that stated, the more difficult part will be to get a job. As you probably know, jobs are hard to come by these day, especially in banking and finance. Since 2008, the banks of America have taken a big hit and it will take years before they are solid again. For example, Goldman Sachs and Morgan Stanley are still letting people go this year. So, some of our premiere banks are still in the process of downsizing.
In light of this, what you will need to do is excel and distinguish yourself through academics and experience.