You should be able to see the account on your credit reports, and it will show when each account was opened. If Citi is reporting it as a new account, it safe to assume that's how they classified it internally. However, since the bonus language changed from "opened" to "received a new cardmember bonus" the new account isn't relevant.

In the particular example the "closed" account is also not relevant for bonus purposes, because it's not one of the cards specified in the terms.