cruisercamper

I had no problem getting the $100 OBC for our cruise in March 2016. In fact I was surprised how fast it was approved and applied to the account. It is combinable with the BOGO sales but not combinable with anything else such as the current $100-200 instant savings or the free gratuity promo.

From Coastal Kitchen, Anthem, March 2018

From Oasis in Feb 2018

If it's for a North America cruise you should be fine. There are some counties that require that you have 6 months before your passport expires, but since you're in transit, it won't likely be an issue as you could use a DL and birth certificate, too.
 
For what it's worth, I'm waiting until after our Allure cruise in January 2017 to renew my son's passport that expires in February 2017.

To re-enter the country your passport must be valid (not expired). I think they say six months in case there is a delay in your trip, such as a ship emergency or perhaps you get sick or injured and there is a delay in returning to the US. Four months should be ok in my opinion. If you are a US citizen you may want to consider also bringing the alternative documentation, such as a birth certificate and photo ID just in case Royal Caribbean decides to be fussy when you check in.

the Soda Package is included in the MDR. If you have the package you just show them your seapass card and instead of bringing you a can they bring you a fountain soda. Once you finish that glass and would like another they gladly bring you a refill.