As you fight in Alterac Valley, you earn reputation with either the Frostwolf Clan for Horde or the Stormpike Guard forAlliance. There are two vendors for each faction; one inside Alterac Valley and one outside in Alterac Mountains. For the Alliance, the NPC within the battleground that sells vendor rewards is in the Dun Baldar South Bunker.
Note that in Alterac Valley all reputation with the Frostwolf Clan and the Stormpike is shared amongst all combatants, whether or not they are partied with you. However some turn-ins will give reputation with one of the four main primary factions. This faction reputation is not shared.
Stormpike/Frostwolf reputation is gained in the following ways:
Killing Enemy General (389 Rep)
Killing Enemy Captain (125 rep)
Killing an Enemy Air Master (5 rep)
Killing any Enemy Guard (5 rep) *NOTE: This is capped through honored and does not give rep in revered*
Killing an Enemy Player(+1 Rep+HK+CP).
Killing Ivus the Forest Lord or Lokholar the Ice Lord (125 rep)
Destroying an Enemy Tower (64 rep)
1-time quests (first turn in of each repeatable, capture a tower/mine/graveyard, etc.) (~100 rep each, varies) ¡ª
Repeatable reputation quests
Ram Hide/Frostwolf Hide (2 rep each)
Bringing a Frostwolf/Ram to your stable (1 - 3 rep each)
Armor Scraps (1 rep for 20 plus 10 Orgrimmar/Ironforge plus 5 rep of the other factions(for every 2 turn ins)for the character)
Storm Crystals/Stormpike Soldier's Blood (1 rep for 1 plus 10 Orgrimmar/Ironforge plus 5 rep of the other factions(for every 2 turn ins); 5 rep for 5 plus 50 Orgrimmar/Ironforge for the character)
Slidore/Guse (1 rep)
Vipore/Jeztor (2 rep)
Ichman/Mulverick (5 rep)
At the end of the game, extra rep is gained for each of the following conditions: