openvpn as a bridge for several vlans

[jp.otto]

Hi,
I'd like to setup two pfSense - Boxes to bridge several vlans through openvpn.
I know I have to create a bridge on each side. But is it just one bridge for the whole interface or do I have to create one bridge for each vlan?
Could someone point me to an example where several vlans are bridged?
tia,
J-P