QUESTION: How can I zoom into the controller lane so I can see pitchbend data more closely?
ANSWER: Cubase has sliders on the bottom and right side of the MIDI clip that allow you to control the scale of the window's content.
Note that the horizontal slider at the bottom of the window controls the horizontal scale of both the controller lane and the note editor regions. By contrast, the vertical slider is part of the note editor region; sliding it up and down changes the zoom factor of that area only.
Try these steps to adjust the areas to your liking: