Since the JReviews listings are just articles, I believe you can use the Social administrator area of JFBConnect to set the comments to automatically show at the bottom of those listings. If you need more information or help, let us know.
If that doesn't work, you'd need to modify the JReviews template file and add the {JFBCComments} tag to the bottom of the listing area which will be translated by JFBConnect and display the Facebook comments box.
Hope that helps,
Alex