Hi-

I've done these flights multiple times.

As noted, everyone of age gets a free glass of beer/wine. Usually these segments are long enough for a free refill. They also have typical soda/juice/coffee for all.

Everyone gets a little cracker mix package.

Normally on these flights they also have one or two of their snack boxes for sale, details of the boxes are here:
https://www.alaskaair.com/content/tr...yond-food.aspx

I like flying STS. The airport is very small, super easy to get in and out of.

Enjoy your trip.