An /interface vlan object merely inserts the specfied VLAN tag for packets on ingress and removes them on egress.
When configuring a Mikrotik device as a switch you may have various untagged and tagged VLANs configured on several ports, but only a single VLAN configured to transit the bridge-to-CPU port for management access to the device.
The VLAN management is currently being reworked so in future adding an /interface vlan to a bridge will automatically add the bridge-to-CPU port as a dynamic entry under /interface bridge vlan. In the meantime http://forum.mikrotik.com/t/routeros-bridge-mysteries-explained/147832/1 written by @sindy is a good explanation.
How have you configured your bond? Only 802.3ad and balance-xor bonding modes are hardware offloaded, other modes will use the CPU’s resources. The built-in switch chip will always use Layer2+Layer3+Layer4 for a transmit hash policy, changing the transmit hash policy manually will have no effect. See https://help.mikrotik.com/docs/display/ROS/CRS3xx,+CRS5xx,+CCR2116,+CCR2216+switch+chip+features#CRS3xx,CRS5xx,CCR2116,CCR2216switchchipfeatures-Bonding