No, the tips for room service are not included as part of your tip "package". A reasonable tip would be a couple of dollars, maybe three if you feel generous. It doesn't make any difference if you are in a junior suite or ordinary cabin - the effort to deliver the room service is the same.
Yes there is a menu in your room and it is free plus a tip. We usually do $1/person. We also had a printed breakfast form with items to choose from and a time for delivery in the morning. Just hang it on your door before going to bed.
Teresa and Larry
#36-Carnival Splendor 9/16/12
7 night Mexican Riviera
#37-Allure of the Seas 11/11/12
7 night Eastern Caribbean
When I was on the Serenade of the Seas and had the information channel on, they showed room service being delivered and the waiter was tipped $2. Since RCL paid for this to be made, I assumed it was a subtle hint that $2 was an appropriate tip.