You may have already figured this all out, but here is what I found.
Amtrak has onboard racks on some trains. You need to contact them for a specific route. If onboard racks are not available on the route you will need to box bike and check as baggage. However, checked baggage can only be dealt with at certain major stations. Anniston is not a check baggage station, it is essentially a flag stop. I don't know if the Crescent has bike racks. This link tells it all.
http://www.amtrak.com/servlet/Conten...554487&ssid=43