X-Treme X-Men had planned to have a series of 6 covers that joined to form one large image. While Bishop, Sage, Storm, and Cannonball appeared on the covers for issues 20, 21, 22, and 24, the covers for Gambit and Rogue were never published.
Oddly enough, the Gambit cover did appear on the Amazon listing for the
X-Treme X-Men Volume 6: Intifada trade paperback, although it was not used for the cover.
To date, the Rogue art has not been used anywhere, but finally Salvador Larroca's original art can be seen here!