official ruling on compatibility between prestige class and standard class ability

[Jon Steele 983]

How does the swashbucklers tarry/re post ability work in conjunction with the duelist re post ability.

[Manly-man teapot]

He can repost once as a duelist, but if he tarries long enough, he can repost again, on the same or different network.

But seriously. The two abilities don't interact at all, and they don't spend the same limited resources. They are each declared after an attack is declared but before it is rolled. The defender can declare one of them and roll it, and then either wait for the attack roll, or decide that they are unsatisfied with their roll and use the other ability as well.