Here I give you some useful rules to limit traffic through a Bridge using mangle and queue-tree in Mikrotik

1. ## Reglas para límitar el tráfico en un bridge Mikrotik ##
# Se marcan las conexiones y paquetes
/ip firewall mangle
add action=mark-connection chain=prerouting comment="Marca Conexiones y paquetes
de subida" disabled=no in-bridge-port=ether3-slave-local new-connection-mark=
ether3_cnx passthrough=yes
add action=mark-packet chain=prerouting connection-mark=ether3_cnx disabled=no
new-packet-mark=ether3_up_pkt passthrough=no
add action=mark-connection chain=postrouting comment="Marca Conexiones y
paquetes de bajada" disabled=no new-connection-mark=ether3_dw_cnx out-bridge-port=
ether3-slave-local passthrough=yes
add action=mark-packet chain=postrouting connection-mark=ether3_dw_cnx
disabled=no new-packet-mark=ether3_dw_pkt passthrough=no
# Se configuran las Colas en árboles Padre y Hijo
/queue tree
add burst-limit=0 burst-threshold=0 burst-time=0s comment="Padre de Bajada"
disabled=no limit-at=8M max-limit=8M name=Bajada_ether3 packet-mark="" parent=
ether3-slave-local priority=8
add burst-limit=4M burst-threshold=0 burst-time=15s comment="Hijo de bajada en
la interfaz del bridge" disabled=no limit-at=3M max-limit=3M name=queue2
packet-mark=ether3_dw_pkt parent=Bajada_ether3 priority=1 queue=default
add burst-limit=0 burst-threshold=0 burst-time=0s comment="Padre de Subida"
disabled=no limit-at=8M max-limit=8M name=Subida_Total packet-mark="" parent=
global-in priority=8
add burst-limit=4M burst-threshold=0 burst-time=15s comment="Hijo de subida en
la interfaz del bridge" disabled=no limit-at=3M max-limit=3M name=queue3
packet-mark=ether3_up_pkt parent=Subida_Total priority=1 queue=default