First off, that's a beautiful wrasse you've gotten yourself.

Second, we have had some success with persuading our fish to get along when it is a grey area of compatability. Every fish seems to have its own temperament that can vary a lot within a species, and then there is the issue of how crowded things are in your tank. It does not seem very risky to try to introduce the second wrasse in your 150g tank.

To improve your odds, try introducing at lights off time. If they are giving each other any trouble, have a piece of egg crate handy to section your tank into two halves. After about a week of this eyesore, you can remove it and the two fish should be used to each other and do fine.

Good luck!