The Rivers of Light dining package is great package for eating at select Animal Kingdom restaurants and getting a good seat for the show. The package includes a seat in reserved seating area (which is filled at a first come first serve basis) at the Rivers Of Lights show at Animal Kingdom.
The Rivers Of Light dining package is available at these Animal Kingdom restaurants:
Tusker House (1 table service credit per person)
Tiffins (2 table service credits per person)
Some people assume that if they eat at these restaurants they're entitled to the Rivers Of Light reserved seating area, but this is not the case. Just booking to eat at the restaurants does not give you access to the reserved area, you must book the Rivers Of Light dining package for the restaurant you want to eat at.
When you're having your meal, your server will give you a voucher which will give you access to reserved seating area when it's showtime. The entrance to this seating area is opposite the Finding Nemo show building in between Dinoland USA and Asia.
For Disney Dining plan guests, it costs no extra! You pay the same dining plan credit as you would eating at one of the restaurants normally. So if you're on the dining plan, you may as well take advantage of this package if it's available. If you're not using the dining plan and paying with cash, there is sometimes an extra cost–around $5 per person–added onto the meal price for this package. These dining packages do sell out quickly, so make sure you get it booked as soon as you can.