I just purchased Elite Dangerous for my xbox, and it comes with a redeem code for Elite Dangerous Horizons. If I redeem it on one Xbox live account, can I still use it on a different Xbox account?
I tried it out myself, and Elite Dangerous: horizons season pass does game sharing on the xbox one.
No, it will be account-bound to whatever account redeems it, like most other XBL purchases.
I can also confirm that, at least when it launched, Horizons did not game share to other users on your "Home" console.