Moss on the north facing side of the tree, yes kinda. Each specific moss will look for the best place to thrive in Nature - north-ish how about that? Winter is a good time to collect a little moss for a display bonsai. Plan to care for the transplanted moss, properly diffuse -north - sun and ample moisture. In later winter apply the moss to the surface of the pot you are wanting to prep for display and make a T-pin of a piece of wire and pin the moss down in a couple of places. Remember that if the moss thrives than the plant is getting more than some trees like so I don't try to always have good moss on my bonsai. Just trees that may go into a show than after not water for such lush moss. Trees need to drain well and get a little dry especially pine. In nature more lichchen will associate with pine and moss more with deciduous plants that want even moisture.

The backyard bonsai courtyard. I bed in sand than buffer wind with burlap from the stronger wind direction.