My understanding is each bearer is its own RLC entity. A particular bearer will be one of the types such as TM, UM and AM.
In normal case (without MIMO), eNodeB schedules one MAC PDU for an UE but one MAC PDU header consists of multiple MAC PDU sub headers and each MAC PDU sub header carries the information of embedded MAC SDUs.
When eNodeB MAC asks for RLC PDU, RLC entity of each bearer prepares RLC SDU and sends to MAC layer.
This way my perception of RLC is that per TTI MAC can send multiple RLC PDUs for each UE.
Please make me correct if my understanding of RLC entity is wrong.