Surprise accuracy:
Benefit: The barbarian gains a +1 morale bonus on one attack roll. This bonus increases by +1 for every 4 levels the barbarian has attained. This power is used as a swift action before the roll to hit is made.
Opportunistic gambler:
Benefit Effects that grant you morale bonuses persist 1d4 rounds longer than they normally would as a result.
My question:
How do these two interact? Does "one" attack roll get the bonus for 1d4 rounds? So hypothetically if my barbarian has a BAB of +6/+1 that for the 1d4 rounds I get the bonus on which ever iterative I apply the morale bonus to initially?