I finally had a reason to take another look at the Rune of Striking in a bow. Recall that when it first came out, the Rune of Striking did not affect bleeds.
The Rune of Striking now also increases bleed damage in a hunter bow.
As before, the amount of the increase depends on the initial DPS of the bow because it adds a fixed amount, not a percentage, to the base damage. For a maxed bow like mine, the amount is nominally almost 5% for the Rare Vanguard Rune of Striking, and almost 6% for the Incomparable Vanguard Rune of Striking.
However, the actual amount varies by skill and is 2-3% for the Rare and 3-4% for the Incomparable. It is surprising that for bleeds, the Rare adds about 4% and the Incomparable about 5%.
Previously, I used a Rune of Force because it increased all skills including bleeds compared to the Rune of Striking. I have now switched to a Rune of Striking. You can decide whether the extra 1% damage is worth the 600+g difference in price on AH for the Incomparable vs the Rare.