As is stated by the last Lion Turtle, Energybending(Eb for short) is the art of controlling the energy or chi in one's self. Also the idea of "energy" is shown to mean any form of energy, for example the Lion Turtle passes knowledge to Aang through energybending.
When Aang took Fire Lord Ozai's bending away, he, Aang, had control over Ozai's chi and then proceded to take away his bending. From this we can deduce two things, one energybending is not limited to energy/chi in the bendinr in question. Secondly, all bending is realated to energy in someway, some more than others.
This blog is uncomplete