Dnsmasq - resolving names through certain interface

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).

What could be the problem ?

Are you running the default dnsmasq or did you install dnsmasq-full?
Other than that it could be just omitted to save some space.

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)"

does it work in /etc/dnsmasq.conf?

No, the same effect
server=/somedomain/8.8.4.4@eth1.121