Body mists can be made by boiling any herb in water and then waiting to let it cool and transferring into a spray bottle, I would be careful about this since plant matter in this form could potentially be harmful if not used fast enough and degrade, kinda like if you leave out a cup of water or tea for a long time. Maybe someone here has tips of how to preserve something like that?
Would also be cool to make a salve or infused oil out of it!
Another option would be to tincture the rosemary in a clear grain alcohol. Let the herb step in a cool dark place for a few days, strain, and bottle securely. Alcohols evaporate more quickly than water and may carry the scent better, plus it will last longer as a preserve.