Wildhammer Clan
Though not a part of the Alliance, the dwarves of Aerie Peak have opened their doors to it and hold the Horde as enemies.
Raising reputation
Quests 0
No quest in the shared quest caches rewards Wildhammer Clan reputation yet.
Quests whose reward, in the game's own quest cache (build 1.60.1.70374), includes Wildhammer Clan reputation. Amounts are the base the game's QuestFactionReward table gives, before racial bonuses. The list grows as players share their caches.
NPCs 0
No quest giver for these quests recorded yet.
The game does not say which faction an NPC belongs to, so this lists the NPCs that give or take the quests above, as Zephras Collector uploads recorded them (accepted and confirmed by a trusted account or two independent ones).
From the WoW Forever game files, build 1.60.1.70374.