There is a general consensus that having the bishop pair when you opponent does not is a slight advantage. Is there any advantage to the knight pair in general?

Having the knights is an advantage especially in the early game because it allows mobility when so many moves are blocked with pieces.  Also knights have the ability to fork the king and other pieces.  In the end game their advantage becomes more of a disadvantage.  They can only move three spaces at a time and covering large territory is better done sometimes with two bishops.  In any case it largely depends on the board and skill of the player using the pieces.

 One advantage is that the strength of the knight pair is often underestimated by members of the 'general consensus'.

This can happen even in the games of strong Grandmasters.

A case in point is the game  Fischer v Larsen , Santa Monica ,1966.

In a middlegame with all the heavy pieces still on, Fischer ( with two bishops and no knights )  got himself whacked by Larsen ( with two knights and no bishops ) in thirty moves.

In blocked positions a knights roto-chromatic movement can be an advantage over a bishop momo chromatic movement (bad bishop vs knight).  Many middle game books go into this.