As you know Fang Pendant adds Pierce; my question is, if I shoot with a bow to an enemy that is not in my space, does pierce from Fang Pendant trigger or not?

as long as you have a success with agility to pay for it you can add pierce.

That's clear, but the pendant doesn't have the "ranged symbol". This is why I have this doubt in case you are attacking an enemy that is outside your space.

o, right. Without the ranged symbol I doubt you can use it with a ranged attack to hit outside your space.

Fang Pendant counts as a separate weapon card so it won’t benefit from a bow’s ranged symbol.