My 34E also came with the bar inside of the panty cabinet, (and absolutely no explanation during the delivery walkthrough)! And there was no sticker explaining it's use.
What I later discovered by watching some 34E YouTube videos, (advertising by various dealers selling their 34E coaches), is that they demonstrated it being placed on top of the large sofa/dinette slide when it's retracted.
It's placed on top of the slide, behind the trim molding, right about the middle.
Now that you mention it. I now have about 8,000 miles on my 2014 34E Hurricane. It's been driven from Florida to California. It's been up to the Eastern High Sierras, and down to Death Valley, and all over the mountains of Southern California and, I completely forgot that I even had the bar, so it's never been installed. Ooops.