Pet skills that stacks with other toons skill

[:1]Id like to know wich special habilities stack with other characters skills in order to select the pet wich helps my teamates to achieve a higher DPS output. For example, how can i know if Tendon rip from hyenas helps fury warriors or rogues. Or the Cats roars wich give agility and streghn boosts the entire team if there is a Shamy. People always tell me to swich pet since there is already a shaman or a warrior so my pet aura wont help, if this is true why would blizzard put skills that improve bleeding effects if none of my skills works with that
If you look at the comments here:

http://www.wowhead.com/spell=93435#comments

there's a list of all the buffs across classes and specs. Unless you're a BM hunter, you're going to be mostly choosing between a cat and a wolf for group buffs.
The pet abilities do not stack with the buffs/debuffs brought by other classes that accomplish the same thing. For example, Roar of Courage does not stack with Horn of Winter. They are meant to be replacements/substitutes, not supplements.
Get the addon Raid Checklist. It highlights in green all the available buffs, and tells you who is providing them. The buffs that aren't provided, but that you are able to provide with the pets you have, are highlighted in blue. Very useful. It'll also say what class/spec/pet can provide each buff, in case you're wondering what pets have what.
http://wow.curse.com/downloads/wow-addons/details/raid_checklist.aspx