Which interfaces did you (or the system that you have installed) assign to br-lan? You shouldn't assign a interface to batman twice (by itself and as part of a bridge)
I'm a bit unsure about which interface to use. Now, I've switched to freifunk to try to facilitate things. It's a new set of interfaces (similar but different).
br0 eth0 eth1 vlan0 vlan1 lo
and on the machine with the internet connection
tun0 tun1
netstat -rn for the machine with an internet connection tells me: Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 br0 10.0.2.0 0.0.0.0 255.255.255.0 U 0 0 0 vlan1 0.0.0.0 10.0.2.1 0.0.0.0 UG 0 0 0 vlan1
Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 br0 10.0.2.0 0.0.0.0 255.255.255.0 U 0 0 0 vlan1
or most recently.... Destination Gateway Genmask Flags MSS Window irtt Iface 10.0.2.100 192.168.1.2 255.255.255.255 UGH 0 0 0 br0 192.168.1.2 0.0.0.0 255.255.255.255 UH 0 0 0 br0 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 br0 10.0.2.0 0.0.0.0 255.255.255.0 U 0 0 0 vlan1