I have tested in R2014b and showPointCloud does work.
If ver('Vision') shows the product installed, it is possible that you do not have it licensed. See what license('test','video_and_image_blockset') returns: it should return 1 if you have the product license. Also try
which -all showPointCloud
if the software is installed but there is no license for it you will probably see a note about no license beside it.