Shepherd's Aspect help

What exactly work Shepherd’s Aspect?
Additional damage is+10% for wolf’s skill, +10% for Raven skill and +10 for poison creeper skill?
Or +10% for every Wolfes every raven and every poison creeper?

And why in my core skill description damage nothing changes when i use this aspect and use my companions?

10% per wolf, raven, vine, so you run it with Stampede to get the most out of it.

As stated it is the bonus damage %(x) PER COMPANION. So 10% per wolf (2 default 3 with Stampede aspect) etc etc. When you use all 3 companion skills in your hotbar (with Raven skill to add 2 more Ravens) you will have 6 total companions. With stampede you will have 9 total. Then you have 9x 10%(x) damage. If you put the Sheppards aspect on a 2 hand it 9x20%(x) this is what I am doing currently.

And why in my core skill description damage nothing changes when i use this aspect and use my companions?

It is applied to the ALL skills base damage as a multiplier. You wont see the increase in the skills damage number but you WILL see a huge jump in total damage output.