Stat this item out for me.

[Weiser_Cain]

In 3.5 if that makes a difference.
It's a spike that when stabbed into a creature, enhances it's intelligence like an awakening spell and creates a touch telepathic bond between both parties.

[Milskidasith]

In 3.5 if that makes a difference.
It's a spike that when stabbed into a creature, enhances it's intelligence like an awakening spell and creates a touch telepathic bond between both parties.

What parties? The spike and the creature? The creature and the guy stabbing it?

It's simple. It creates an instantaneous telepathic bond spell between the stabber and the creature, along with casting the awaken spell on it. I'm not sure of the cost, but the item itself is literally just two spells in one stab.

[Hyooz]

Seems to me you've got it statted out already.

[DracoDei]

Is the duration of one or both effects limited to however long the spike is in the creature?

I might recommend saying it doesn't hurt and/or deals no hit-point damage. Otherwise you are worsening relations with the creature at EXACTLY the wrong time, and depending on how feral the 3d6 intelligence is (it is possible to be quite feral with a very high INT) it might not stop to consider where its blessing of intelligence came from before it deals with the perceived threat of the person who just hurt it.

[Weiser_Cain]

The effect is with the stabber and the creature, the effects last as long as the spike is left in place, if removed the animal reverts to normal but retains memories gained during even if it doesn't understand them completely so that with a decent check you could in a pinch reinsert the spike without being killed right away.
I was working on a ritual to keep you from being gored (by the elephants I intended this for) during the first joining and to add more people to the list that can connect to the animal.
Are you sure this doesn't qualify as a minor artifact (even though I intend to make it unclear if this is a straight up magical item)?