Should a page be created for settings that don't have a strong effort of conversion behind them? I added a monster from Glorantha (the Runequest setting) and will probably add a bit more Glorantha stuff, but at the moment I have no interest in pumping out a lot of conversion notes. Should I make a Glorantha page or are tags enough?
Adding tags is a good start. But if you have the time, by all means add a page for Glorantha which lists all pages tagged this way (the existing index pages should give you an idea how to do that).
Even if you don't do anything more than that, this is still a wiki - someone else might just continue the work on the setting.