No, the Ninth Circuit 3-judge panel ruling is not going to be reconsidered en banc in the Ninth Circuit.
The Ninth Circuit is a Federal Court of Appeals that covers Alaska, Washington, Oregon, California, Hawai'i, Montana, Idaho, Nevada, and Arizona. An en banc rehearing is not equivalent to "the state level", which would typically be construed as meaning "under the state court system". The sole portion of the Federal Prop. 8 litigation that involved a court at the state level was a certified question to the California Supreme Court on whether the defendants-on-appeal had standing under California State Law (they are).
Typically, an en banc rehearing panel consists of every judge in the circuit. Because of the large number of judges in the Ninth Circuit, an en banc panel consists of only 11 of the 29 maximum number of judges. No other circuit (1–8, 10, 11, DC, Federal) has more than a maximum of 178 judges.
Just as an added note to the title of the post, there is no right to appeal to the Supreme Court for this type of case. The Supreme Court has complete discretion on whether it will hear this case or not. I can't see the Court not granting certiorari in this case, but there is no appeal by right.