In all my years in the commercial kitchen I've never heard of the "bag 'em with bananas" trick and now I'm dying to try it. We use lots of kiwis.
Up to now we've been keeping them in a low-room-temp dry storage area (right next to our tomatoes and avocadoes) and we pick out the ripe ones and leave the rest for another day.
Tomatoes and avocados produce ethlyene gas and should speed up the kiwi ripening process, but kiwis also produce ethlyene, so you have a very synergistic ripening environment in your storage area. No need for banana-bag trick, you've got it right.
Actually, bananas and apples are not only ethlyene producers but are also ethlyene-sensitive and should be kept away from ethlyene producers.