You can see most of the show from one of the Japanese restaurants, but I'm not sure if it's a TS one or the CS; and you can see most of the show from the glassed-in area of Chefs de France if you can get a table at the window.
Even if you can't get an outside table at Rose & Crown (you can ask, but you cannot offer to wait for one to become available), your server will direct you outside to a viewing area that does not block the patio-seated diners.
But really, seeing Illuminations is a, um, less than desirable reason for choosing a restaurant. What if you don't like English food? Or at least, anything on the Rose & Crown menu? Then you've wasted money or dining credits for what may or may not be a good view, depending on the wind.
A better suggestion would be to dine at a restaurant whose cuisine you enjoy, early enough so you have time to scope out a good viewing spot around the Lagoon. Last week, there were a LOT of good (empty) spots in the Germany Italy United States China Morocco France area.