
I distinctly remember testing this thoroughly in retail vanilla wow so I am 99% sure that I am correct in this but it is hard to find good reference. I was only able to find 1 reference and it's not perfect but hopefully it is enough.
In vanilla wow talents like Spiritual Healing in the priest holy tree and Gift of Nature in the Druid resto tree were applied BEFORE +healing from gear. That is, they did not stack with gear.
The talents that I am talking about are anything that say:
"Increases the effect of all healing spells by x%"
Talents that increased damage where always applied AFTER +spell damage from gear. That is, they DID stack with +spell damage from gear.
This was either changed in a later vanilla patch (1.12) or it was changed with 2.0.
The only reference that I can find is this:
"* All healing talents in BC are multiapplicative and also include +healing effects."
http://www.blizzhackers.cc/viewtopic.php?p=2716940 - 2nd last post on the page.
I can't see anyone bothering to mention that healing talents are multiplicative AND include +healing effects if that was already how it worked. Especially in a post that is entirely "what to expect in TBC".
Can anyone help me find additional references that prove or disprove this?