Hi Sen, and welcome to planDisney!
How jealous I am that you get to enjoy a beautiful night of yummy selections at the
California Grill at Disney’s Contemporary Resort! Congratulations on snagging that
Walt Disney World Resort reservation.
If I were to choose, I would recommend the later reservation at 9:40 PM, just so that you have time to sit and enjoy the entire experience. To answer your question, you are most certainly welcome to view the
Disney Enchantment fireworks from the observation deck; just let the cast member know that you have a reservation, and they will let you know how to proceed. Be sure to arrive early, maybe about 8:45 PM, so that you can secure an excellent spot to enjoy the show then enjoy your meal right after.
Please return if you have additional questions; we are here to help.
Have a magical meal!
Raquel