Yes they have concierge services. Everyone, no matter what room category they've booked can use the services. No class system at Couples. Everyone gets treated well and taken care of at Couples. Not just the guests who pay more for their room.
No class system at Couples, everyone is treated the same and gets the same concierge service no matter if they book the least expensive room or the most expensive suite. That is one of the many things we love about Couples.
It's just a concierge desk. It never had anymore than one or two couples at a time. We never saw a need for our "own" concierge person. Bags are taken to your room, cabanas reserved yourself, dinner reservations made at concierge desk. It's nice everyone is made to feel equal and special. We never had trouble reserving anything. But cabanas do go to the early risers, but we moved around the beach a lot anyway and there was ALWAYS shade somewhere so they were not necessary for us.
I think that the OP may be thinking of concierge service in line with what some other AIs present. When we stayed in the DR, we could pay $50 extra/night for concierge service. This was quite separate from what I normally think of concierge service (helping with reservations and excursions). The concierge service at the particular place we stayed at in the DR would provide priority status for dinner and sunbed reservations.