I would expect this command to return the gid for this group.
Indeed, while the domain groups are working: bin/wbinfo --group-info='domain admins' Domain Admins:*:3000000: you are correct to note that, local aliases do not appear to be: failed to call wbcGetgrnam: WBC_ERR_DOMAIN_NOT_FOUND Could not get info for group administrators
That's not a highly critical issue but more something that should be fixed eventually. At a first glance it didn't look like it's too easy to fix it.
In "master".
this particular issue, that we do not look up domain aliases, is not yet in master
wbinfo --group-info='BUILTIN\administrators' (note the right domain also) works correctly, tested with 4.12