The Wonder is alot more casual than the Magic.
More do dress up on the Magic than the Wonder, but you will see all manor of dress. The clothes you described will fit in nicely for formal night.
You dont see many tuxes but you will see a lot of suits and many ladies will be dressed up. Some are pant suits but they are dressy ones. I always see several long dresses too. Usually black ones.
Palos use to require jackets. They no longer do that but most do wear them. They do require a nice dress shirt and tie for men with slacks of course. Women a nice outfit. So it is not formal but it is nice dress and they unlike the regular dining rooms will send you away to change clothes if your not dressed properly.
On the DCL website they do have the dress code listed, that is where I read jackets are no longer required for men. We have our first Palos ressies for our Nov cruise and I wanted to make sure hubby was dressed properly.