Hmm... items.xml should give the answers, but the damage setting is spread between the weapon and the ammo types, and not exactly knowing how they interact isn't going to let me give a great answer.
The 'basic' bolts have damages 50, 59, 63 (stone, iron, steel).
The comp crossbow (items.xml:5428 gunBowT3CompoundCrossbow ) has a damage of..:
<passive_effect name="EntityDamage" operation="base_add" value="13.5" tags="perkArchery"/> <!-- damage offset -->
<passive_effect name="EntityDamage" operation="perc_add" value="-.15,.15" tags="perkArchery"/> <!-- random EntityDmg -->
<passive_effect name="EntityDamage" operation="perc_add" value=".1,.5" tier="2,6" tags="perkArchery"/> <!-- tier bonus -->
So supposedly, 13.5 * 1.5 +/- 15% for a quality 6. That's 17.21 to 23.28 damage for the bow.
If you're sporting steel arrows, adding 63 wouldn't get us past 86 .. so there's some way to calculate all that, but you'll need to test quite a bit to come up with the actual formula.
You can probably see why I just want to shrug now ...
EDIT: I seem to recall some testing that lead me to believe that the effect of skills was shown on the tooltip, but the effect only altered the damage of the ammo (was testing guns, but it looks like bolts are set up similarly).