Unfortunately the functions of Set Tag and Set Address are not part of standard NI-FBUS CM API library; in fact, these functions and other advanced configuration functions are included in the "Configurator" API library, which is not free of charge.
If you want to know more about these functions and the "Configruator" API library, I suggest you contact "fieldbus.support@ni.com" directly.
Hope it helps.
BTW: If you use LabVIEW, the NI FF-LV library supports Set Tag and Set Address.