There are two schools of thought on this, as far as I've seen. First is dry-hop after fining with gelatin. Your beer will probably still have a little bit of hop particulates floating around, but you'll get exactly what you intend (or at least, what you performed) from your dry-hop. The second is dry-hopping before gelatin. You might lose a little bit of the flavor by fining after dry-hopping, but your beer will be clear. Hope this helps.