In GTM (or new name DNS), you can answer DNS queries dynamically or statically.
Dynamic is using the wide IPs, while statically is using BIND.
ZoneRunner is just a front end for BIND.
When using the GTM (wide IPs), the system will take decisions based on how you setup the wide IPs and GTM pools.
Also, as an example if using LTM, it will check that the virtual server is UP, if not, it will not send response with that virtual server IP.
When answering via BIND, that is static, independent of the virtual server status it will send the virtual server IP.
Wide IP supports a limited number of resources types (like A,AAAA, etc...), while BIND supports almost all types in use (if not all).
So, you may be in a situation that you can't use wide IPs for the resource type you need to setup, so you need to use BIND.
The system will also by default try resolve the name via wide IP, if not possible, it will use BIND.
That is configured in the DNS profile setting "Use BIND Server on BIG-IP", also in the GTM pool setting "Return to DNS".
One important troubleshoot information, GTM (wide IP) answer normally has a TTL very small, as you want the client to come back so you can check if the server still UP.
BIND on the other hand, as it does not care about status, has a larger TTL, just to allow changes of IPs for example.
So, when query a name, you can guess if is GTM (wide IP) answering or BIND based on the TTL value.
GTM default is 30 seconds, BIND TTL default in GTM is 500 seconds, normally is larger in other systems.