Wearing a white marcella vest like this with a dinner suit is entirely correct; it's a more formal halfway point between black tie and full dress. You can see a good example of this in the classic movie "The Thin Man," when William Powell wore the combination at the dinner party near the end. However, this only works with a stiff- or semi-stiff–front shirt with a high, detachable wing collar (like the one offered by Brooks Brothers)—and a self-tie black tie. It's never appropriate to wear a white evening bow tie with anything but full dress (tailcoat, &c.).

The buttons are sewn on.