Playing the game after saving through the game and then turning the Wii off will, just like the SNES version, reduce your lives back down to five and reset your bonus score back to 0/100.
You can actually save both the amount of lives you have and your bonus score for the bonus game if you use the 'Suspend' feature. When you're finished paing, press the HOME button on the Classic Controller/Wii Remote, and select Wii menu. When you return to the game later on, you will be able to start where you left off with the same amount of lives you had and the same bonus score you had previously.
What's also useful is that you don't have to clear a Ghost House, Castle or Fortrss in order to use this feature. You can suspend whenever you like - even mid level. Although suspend data is lost once you play the game again.