It doesn't matter if you are of age, you are not allowed to bring your own alcohol into a Disney Park with you. If you purchased the bottle in a park, for example, if you bought it during the Food & Wine Festival at Epcot, make arrangements to have it delivered to your room. If you're not staying on property, leave the bottle in your car. If you attempt to bring alcohol into a park it will be confiscated, even if you bought it at Disney. It does not matter what type of container the alcohol is in, it is not allowed. You will also be required to finish your drinks in the park before you leave. You can't take drinks outside of the parks. If you plan to drink, you will buy it in the park and drink it in the same park.