Which exactly RB1100 are you talking about? RB1100AHx4 has RTL8367 and ROS 7.1rc1 added L2 HW offload for this switch chip (7.1rc1 announcement). Which means that properly configured bridge filtering should be handled by switch chips in ROS v7.x (not counting 7.0.x, these are weird beasts).
The new documentation at https://help.mikrotik.com/docs/display/ROS/Switch+Chip+Features also states that VLANs are supported by RTL8367.