They don't. A barbarian with Tireless Rage is still exhausted after using Roused Anger. A barbarian with Tireless Rage can't be fatigued from raging, but it doesn't prevent fatigue from other sources. A barbarian fatigued by another source can still rage using Roused Anger. Similarly, Tireless Rage provides no defense against being exhausted, either by rage or by another source. Basically, the two never interact.