Bonding for Small Gap in Front. I Can Still Feel A Gap. How Does Bonding Work?

Overall I am pretty happy with the result... Is it normal for a doctor to only add bonding to one of the two front teeth to fill a tiny gap? As opposed to adding 1/2 as much on both teeth...the space was small enough so that it doesn't look weird that only one tooth was widened.... My real question however, is: Is the bonding supposed to go the entire thickness of the tooth? I can still feel a little bit of a gap with my tongue on the inside of the teeth, but on the outside it is closed