Lots of candidates will apply for a residency position at a hospital where they interned or had rotations.
I would definitely encourage you to at least look at other programs to help you get a better feel for the variety among programs and identify which are the best fit for you (could be where you're an intern or elsewhere). I think there is also something to be said for variety in your training experiences and going to another institution will give you perspective on how other pharmacy departments get things done.