NFHS Rules: A1 receives the ball at the post position. A1 pivots, takes two steps to the basket and lays the ball up for a score. I am being told that in this situation A1 is allowed the two steps without dribbling. In other situations this would be traveling. I can't find a good explanation for this in the rule book. Is this correct?.

If the pivot foot was lifted and returned to the floor before the ball left the shooter's hand, it's a travel.

The travelling rules don't change just because the ball is in the post.

Was his back to the basket when he cuaght the ball?

If it was, then he didn't pivot. He stepped with one foot and then stepped with his pivot. Bob is right. This is a travel. Kids will continue to do it until we, as officials, crack down on it.