Not able to add system or vision client tags

I cannot seem to link or drag a system or vision client tag to a perspective view?

Those are part of the vision module only. The alternative to client tags in Perspective is session properties. Not sure what will be done with system tags.

I added my “client tags” under the session.custom section on the session config page (the gear in the bottom left)

As others have mentioned, Client (and System) Tags cannot be used in Perspective due to technical hurdles that would lead to a poor user experience. The preferred approach is to use the session.custom area as was noted by Brian. Let us know if you need more information on how this works.