This is an iPad project where I have a UIView with several subViews, and I am trying to animate one of this UIViews using [UIView transitionFromView:toView:duration:options:
Use a container view to hold your subviews, and make the container view the same size as your subview that you're trying to animate.
So, you can setup your views like this.
self.view-> "a container view" -> subviews