Power in Group Prayer

No, you and the other in your group would each “get credit” for praying one rosary. However, there is power in prayerful numbers. When you pray the rosary in a group, the Church provides each member of the group the opportunity to receive a plenary indulgence.

So besides the fellowship and the spiritual bonding that accompany praying together, you have this additional incentive, as the Enchiridion of Indulgences provides.