10/1/2009: Sanguine Bond’s ability triggers just once for each life-gaining event, whether it’s 1 life from Soul Warden or 8 life from Tendrils of Corruption.

However, they’ll both keep continuously trigger each other.

Say you deal damage to an opponent or they pay life or their life total is set to a number below the previous one with both Blood and Bond out.  Exquisite Blood triggers, then you gain life. Then Sanguine Bond triggers, causing the opponent to lose life again, which triggers Exquisite Blood, and so on. Neither of these triggers are optional, so they will continue to happen until that opponent is dead.