I have sailed RCCL and CCL many times and never had to pay for tea, coffee, milk or juices. There is an extra charge for bottled water though. But on both cruises, had to pay for soft drinks. Karen is right, that is the norm on all the majors. The only lines that are truly "all-inclusive" are the 6-star ultra luxury lines (Crystal and Silverseas).
You can purchase a soft drink card for around $30 (I think) that will get you unlimited fountain soft drinks for a 7-day cruise on both RCCL and CCL.
Hope this helps to answer your question.