Yes you can apply a skim finish to the Siniat LaDura plasterboard. As it is a moisture resistant board you will need to pretreat the board with a bonding agent first.Then follow the guidance of the chosen skim product manufacturer.

Siniat LaDura is designed as a robust board and consideration should be given to the type of skim plaster should the finish surface be required to have increased scuff resistance. Some skim plasters may not provide this same level of performance as a surface.

Annex A2 within the Siniat Drywall Manual provides more information on Skim finish.