In my experience, no. This is the tapas culture typical in some areas of Spain. If they are brought to you without discussion, they are complimentary — you only pay for the drink whether you eat any or not. The only way to know if you’ll receive something typically is to ask and there is no harm or insult in specifying dietary restrictions, though they may just bring bread or olives if you’re on a strict diet. Other regions offer them for a cost and that will be clearly marked on a menu. And even in regions that do provide them gratis, there can even be nuance based on what kind of beverage is ordered.