Composite or mixed supply

Mixed supplies because each of these items can be supplied separately.

Alochol for human consumption is not covered in CGST Act , 2017 hence no question of mixed or composite supply . one is governed by state act and other by central & state act.

can't it be wholly taxable at rate as per snacks GST?

you serve alcohol in your restaurant, your taxes are slightly more complicated. The GST regime does not include liquor. That means that when a diner orders a drink, you need to tax that drink at different rates. Depending on where your restaurant is in India, that could include VAT and any other applicable state taxes. These taxes must only be applied to the alcohol part of the bill, while the GST must only be applied to the food section of the bill. It’s important to set tax rates appropriately in your point of sale software to stay compliant.