There are different levels of bonds, as there are different levels of relationships you share with others.

However, with Vulcan's... they share a bond with planet and their entire species...

But it is weak, and a mere presence in the psyche. The one you share with your parents is very strong, and incredibly present in one's mind...

However, the strongest one of all is the one that you share with your mate.

[Spock pauses for a moment, and considers what he will say...] Vulcan's are not known for their casual acquaintances or relationships. 'Friendships' are perceived differently...