While you have every right to send a drink or dish back that you don’t like, if you’ve literally called for a “dealer’s choice” — which means you are asking the bartender to choose the drink for you — you are risking looking like a real jerk.
The entire idea behind the dealer’s choice is that you are willing to leave your drink order up to the bartender, and then drink whatever you’ve been served. If you have parameters regarding the kind of drinks you like, and you still want to order a “dealer’s choice,” then you must provide those up front. Don’t place your order and then announce that you don’t like tequila when the cocktail arrives with this spirit as its base.
While you might think ordering the “dealer’s choice” makes you look cool, you will look anything but if you reject what has been offered. If you have a tendency to send things back, stick to the menu and order what you like.