In fact, Apple still has not adopted the Unicode 7 standard that was finalized in June of 2014, continuing to offer only the emoji that were included in Unicode 6.
I think it was added in iOS 8.2 which was released a few weeks after Leonard Nimoy's death. I wonder why they didn't add it in the stock emoji keyboard. I use SwiftKey and they added it in their emoji keyboard in a recent update along with skin tone modifiers.Actually, the Vulcan "live long and prosper" salute was added from Unicode 7 at some point in iOS 8. I'm not sure which version. It's also in OS X, but perhaps only in Yosemite.
However, it's not on the keyboard. I copied it from a webpage that displayed it, and then associated it with a keyboard shortcut.
This is the one which MacRumors used to have, and still has for me:Yeah, like in iChat, AIM, etc. The MacRumors one is pretty close:
Edit: Here's the iChat one, which MacRumors used to have: