Yes. It is enough to install Studio and Runtime in the citrix server. Once you are you done developing your solution you will need to publish the Runtime so that the end user can access it.
Please note that if you are using Robotics SP1 you will not be able to install both Studio and Stand-alone Runtime on the same machine, as this is no longer supported. In this scenario, you will install Robotic Studio and then use the Runtime executable that is found in the Openspan installation folder.