We currently provide a global VAT / Tax system which allows you to specify the addition of VAT or Tax to all products during a customers checkout . As such it is not currently possible to add VAT / Tax charges to only certain products in your shop at this time.
You can however easily switch off the global tax option and add VAT onto your specific products as part of the total cost.
You could then include some more information about this in your product's description area. For example:
Don't forget you can also display your VAT/tax number in the footer of your website for your customers' convenience.