If there were an FM, I'd have recommended that, but since there isn't, I'll tell you. I do not think that there is a way to center on a specific POI. Obviously, you can single-click on the POI itself if it is in view, but if not, my only recommendation is to zoom out until you see it (you may have to increase the "maximum zoom level at which POI's are displayed" option in Settings), then zoom in on it.

Sorry that there isn't a better way, but I think the use case for POI's is more along the lines of, "What is nearby?" In which case you don't really need a "Center on the selected POI" functionality.

/me shrugs, since he doesn't use POI.