To dream of any religious symbol, means that you are looking for deeper connection with divine aspects of your life. You are trying to make the connection with your spiritual world. Sometimes the dream suggests to become more religious at some point, because you got stuck in material stuff too much. Sometimes very religious people dream of rosary or any other kind of religious symbols because their waking life is very much connected with the beliefs he has. Maybe the dream offers you to become more relaxed and enjoy the life it is.
Read more about dreaming of Rosary in other dream meanings interpretations.