The doc is very confuse about the .jQuery(elementArray) applying. I understand it how you can see on jsfiddle here.
So, I propose this idea. Apparently is easy to make it works and very useful. Currently you need to use .add(eachElements) to do the same thing, and it cost too many bytes, dependings of your application.
But doesn't works with a jQuery collection isn't a bug, maybe?
It isn't a jquery collection, it is a collection(array) of jquery collections (big difference!). That's like saying it doesn't work with an object that contains jquery collections, it simply isn't intended.
you can however combine multiple jquery collections into one collection and use that (which is what i did in the fiddle).