Yes you can see Illuminations VERY WELL! You can even hear the music from the show too!
I have quite a few photos of the show from CBR if you'd like to see them.
Go to:
www.supremedisney.com
Click on the pictures link
Then go to down to "Illuminations from CBR".
if you want to see them from the spot I took those photos, sit on the beach in front of Port Royale. For an even better view (which is where i took the photos) stand up on the bridge right at Port Royale.