multilink bonding questions

I am looking to bond two wireless links. I am currently using nanobridges for the link. Need some advice.

Basically, an rb1200 on both sides, and then two separate links, both of which are nanobridges:


RB1200
Eth1 Eth2
| |
NBA1 NBB1
| |
NBA2 NBB2
| |
Eth1 Eth2
RB1200

I’m looking for the best way to bond these links up.
I want to maintain access to the nanobridges, so just putting eth1 and eth2 in bond1 isnt an option (correct me if wrong)

two ideas I had are:
add a VLAN 20 to eth1 on each RB1200, and a VLAN 21 on eth2 on each RB1200. Put the VLANS into bond1
add EoIP tunnels from Eth1 to Eth1 and Eth2 to Eth2 and put the EoIP tunnels into bond1.

With EoIP tunnels, I need to have separate subnets for each link to keep them straight.
With VLANs I dont believe I do as link monitoring on the bond would be done with arp.

FYI, bond1 on each RB1200 will be put into an HWMP+ mesh on both RB1200s as well.

Additionally, I assume balance-rr is the proper mode to use for this type of link.