it seems like I've heard of a bitch finishing from the Vets class?
Veterans classes are non-regular classes and the winner of each class does not compete in the "Winners" class like the regular class winners do. Only dogs/bitches awarded Winners dog/bitch obtain points toward their regular Championship.
However, GRAND CH points are awarded to those dogs entered in or that that become eligible to compete in the Best of Breed class. Therefore should the winner of the Veteran Class win BOB, BOS or Select Dog/Bitch, then they will receive points towards their Grand Championship IF they are a Champion. So you may have heard about a bitch finishing her Grand Championship from the Veterans Class, but not a regular Championship. I know of many dogs who have finished their Grand Championship from the Veterans class.
since it is a non - regular class, can you enter your veteran in veterans class and also enter in BOB class?
do you have to win the vets class to be eligible for BOB?
If your Veteran is a Champion, then yes you can enter him in both the Veteran and the BOB class. However, if he does not win the Veterans class, then I am not sure that he would able to be shown in the BOB class by virtue of being defeated in the Veterans class. I would not enter both classes. If the show offers Veterans Sweepstakes, I have seen owners enter their Veteran in the Sweepstakes, but then enter BOB instead of Veterans class.
So to answer your second question, if your Veteran is not an AKC Champion, then yes, he must win the Veteran class to become eligible for the BOB class. All non-regular class winners involving a single dog entry, unless otherwise specified, becomes eligible by virtue of winning their class; hunting retriever, field trial, veterans.