Cinnamon bark oil is a dermal toxin, irritant and sensitizer and should not be used on the skin. It's considered one of the most hazardous oils.
Source: The Illustrated Encyclopedia of Essential Oils, by Julia Lawless. I don't yet own a copy of the bible of EOs, which is Essential Oil Safety, by Robert Tisserand. However, Julia Lawless is a known and respected expert in the field. I trust her.
Edited to add: According to Aromaweb (link follows) the dermal max for bark oil is 0.07% compared to the dermal max for leaf oil of 0.6%. Those numbers come from the aforementioned Essential Oil Safety. Given that info, the information on the cinnamon vogue website is truly alarming. But then, they're in the business of selling the oil. http://www.aromaweb.com/essential-oils/cinnamon-oil.asp