When you catalog files CatDV doesn't care where the files are stored as long as it can see them in the file system. They could be on a local drive, on a network share, on a SAN, on a NAS or Firewire drive, etc. If you only have a single user license you can only run CatDV on one machine though.
There are cases where you can do something like that:
If you own 2 copies of catdv, yes, you can create a catalog on one mac and save it to a shared folder.
Then, if the second mac can get access to that shared folder, (and if the media is shared) you can open that catalog and log, tag, sort and view clips just like the first machine did.
However, one note on searching. In the standalone version of catdv, you can only search in the catalog that you are viewing. In order to search across all catalogs you'd need the server.
So, for instance, if I had a catalog with 500 clips in it, I could search for clips within those 500. But if I had another catalog that had related clips in the shared folder, I would not see those clips in my search without the Server version.
We do this a lot for shops who want to start cataloging footage for the future, but note that it's not very useful for managing an archive since you can't search across those catalogs.