According to dnsmasq documentation about --server parameter (http://www.thekelleys.org.uk/dnsmasq/docs/dnsmasq-man.html) I added to /etc/config/dhcp:
list server '/somedomain/8.8.4.4@eth1.121'
list server '/anotherdomain/8.8.4.4@eth1.131'
Restarted dnsmasq but it continues resolving names through default interface ignoring pointed in config and taking into account only ip address of server for resolving (8.8.4.4 in my case).
I use default dnsmasq but I checked dnsmasq-full, this option doesn't work too.
I even can't use:
list server '8.8.8.8@eth1.131'
It goes through another default interface though I see in logs record "using nameserver 8.8.8.8#53(via eth1.131)"