Yes Soda package is still available Along with Wine Package.
$6pp pd for adult soda package +15% gratuity. There is a 'wine and dine' wine package - you can see prices and the wine selection (not great) on the RCI website.
...and you don't have to have the drink in the flask - you just show your card to get the soda. It is fountain soda only out of the squirty pump and not out of branded 'diet coke' tins. No juices are included in soda package. And it is $4pppd +15% gratuity for children under 17.