Is there a fitness center or gym? Any access to bikes or other active/sport options?
No gym , there is lots of cycling around Stellenbosch , bike hire available from : dirtopia co za
There is definitely not a fitness center or gym. There is, however, a swimming pool, the water temperature of which certainly varies upon the time of the year. I kind of doubt that there are bikes, as I haven't seen any, but I encourage you to write directly to the hotel and ask. The hotel's manager, Marika, is extremely nice and I'm sure she would be happy to answer any questions you may have.
Get an answer from Clouds Wine & Guest Estate staff and past guests.