Do you think other volturi members excluding Aro know about Chelsea and corin's power? Like wouldn't they be thinking Chelsea has power of bond would she be using that power on me? Or any suspicion or doubt what they are feeling isn't real because of these 2 members? Vampires are intelligent so they should fit the puzzles quite quickly..
I think they have to be aware on some level, but perhaps they don’t quite know the scope or underlying reasons? Chelsea could rather benevolently be passed off as like “team building!” or and helping a large group of vampires get along without getting into constant limb-losing fights without the darker “soooo we stole you from your previous coven and forced your loyalty, lol” stuff being too too obvious. I think the Volturi do try to sell themselves on the honor, the glory, the privilege. Work with us to uphold the Law! Work with us, get cool robes and live in a castle! Work with us, we’re basically royalty! Work with us, and your eternity will have purpose. There’s a prestige there that works to the Volturi’s advantage–a lot of vampires would probably join up without Chelsea, and then she just …makes sure they’re really, really committed.
Corin… I think it’s pretty obvious what she can do, in terms of ‘contentment,’ but the addictive nature might not be as obvious, especially since so few Volturi guards just up and leave. (I tend to think ones who are replaced are killed, personally. I don’t think Aro and Caius want Volturi-trained vampires who know too much out in the wild). So they wouldn’t necessarily see/feel the effects long term–they come back from a mission and have this weird urge to check in with Corin and suddenly feel better.