Premium Non-Alcohol Package - Can we pay difference to add alcohol to drinks?

[CruisinCooperSt]

Question for the experienced Celebrity cruisers: The premium non-alcohol package includes virgin frozen drinks. Can we just pay the difference to have a shot of rum (for example) added to such a drink or will they charge us for the entire pina colada/daiquiri? Additionally, can we get our non-alcoholic drinks at any bar or just certain locations? Thanks in advance for your help!

[Silhouette2017]

You can order a shot of rum, but it will cost you the same as a cocktail. Celebrity seems to charge alcoholic beverages by the alcohol price only, the mixers are for "free".