My understand of bind in handling non-authoritative queries is:
- forward mode. It just forward the client queries to an upstream DNS server, which is defined in "forwarders" directive.
- recursive mode. It actually start asking from root DNS server, then 2nd level DNS server etc till it finally get an authoritative answer for the host in question.
Non of these modes seems to depends/relates to the system DNS settings on the host which bind is running on, e.g.