We've already talked about how to set up and start using Finder Tags in OS X Mavericks, but what about documents that aren't stored on your computer, but in iCloud instead? It's just as easy to apply Finder Tags to new and existing iCloud documents too. Here's how:
Before beginning, it's worth noting that for either of these methods to work, the app you are using must support storing files in iCloud. Apps like Pages, Keynote, Numbers, and many third party apps have support for iCloud document storage. Just make sure that before you try and save a document to iCloud, the app or program you're using supports it.
That's all there is to it. Just note that some programs and apps may vary slightly depending on the type of app and how the developer decided to lay out menus.
That's it. Your documents will now start appearing under the tag, or tags, that you've specified. Note that you can highlight multiple documents at once by holding down the command key and selecting them. This is convenient for times when you need to tag the same kinds of documents all at once in a batch.