Guest Network (N66U)

I've been converted to Asuswrt-Merlin after running dd-wrt for a number of years, just wanted to say thanks Merlin for an excellent re-spin of the standard (already good) standard Asus firmware.

I current run a custom DNSMasq set-up to enable me to provide different DNS servers for VIPs and NON-VIP users of the network (Adults with registered MAC addresses as opposed to the kids devices who get OpenDNS filtered DNS). This works great as it did on dd-wrt but I now wish to use the Guest Network feature and here-in lies the problem. I would like to publish another set of DNS entries for the guest network users (i.e. non OpenDNS for non-registed MAC addresses) but I seem to be unable to do this given that the Guest Network is simply a bridged WLAN interface using ebtables to segregate form the internal LAN rather than a separately IP addresses interface I could simply assign a new IP range to and then advertise separate DNS entries.

Anyone have any ideas of how I could go about achieving the publishing of different DNS addresses to the Guest Network users as opposed to my users on the standard LAN and wireless networks?

Many Thanks