Yes, you will need to add the additional amount to the "Taxes paid to Another State" in the Credits section of the Kansas return.
It is a credit that is allowed by Kansas, and while most states only allow the State income tax as a credit, Kansas changed the law a few years ago to allow the City Earnings also, so add this amount to the State of Missouri Taxes you are paying for the credit.
http://www.kansascity.com/news/politics-government/article31669076.html
