What did you hear about reverb panning? Are we talking about how reverb distributes reflections across the panorama, how reverb preserves or does not preserve pan position of stereo and/or mono inputs, whether or not a reverb sums left and right before generating reflections, or using panning as a special effect or widening technique?
In lieu of clarification, I'll take a blind shot at the question...assume that the output of a reverb plugin is probably stereophonic, in which case "panning" has no meaning. But depending on how you want to manipulate the stereo image, inserting Channel Tools after the reverb would be the usual starting point. That will allow you to either narrow the reverb tail's image, or use M/S mode to widen the reverb by boosting the sides.