Yes, your rotations do play a part. One of the things I have been told is that an ambulatory care/primary care rotation is a rather important rotation to have if you plan on pursuing a pharmacy practice residency. I've interviewed at a program that requires that the resident see patients one day a week in the ambulatory care clinic as part of your longitudinal responsibilities, and you will more than likely do rotations in these areas as a resident, staffing the anticoag clinic, for example. If you are not required to do an amb care rotation, I would do one anyways.
Rotations should allow you to get from it what you put in it...that's why challenging rotations are best for the residency-bound. Don't pick rotations where you just come in, do a few things and leave, with no feedback from your preceptor (I know of a few). Your CV is improved by being able to list more than the usual everyday stuff in your rotation descriptions. More than likely, you will be asked about an aspect of your rotations, such as any interventions you might have made.
Also, if you know that there are certain connections between preceptors at rotations and preceptors and directors at your desired residency, you might want to take advantage of that. They can put in a good word for you come LOR time, and since they know the director or someone else there, the letter will mean more.
I don't remember ever being singled out because I might have done some rotations at certain well known hospitals (I take that back, I was asked if "so-and-so" was still working at a certain hospital I did rotations at), but I really don't know if the words "Mayo Clinic" on your CV might provoke a response at your interview.
