Their house reef is Oil Slick and as mentioned is a nice dive with super easy entry and exit. It may be the house reef but you want to drive your gear the one block to it.
Oil Slick may be the nearest reef to Caribbean Club, but calling it a house reef is stretching things a bit. Oil Slick's dive site entry is 300 yards downhill and across the road from Caribbean Club's parking lot. In the context of Bonairean diving a "house reef" is typically adjacent to and/or easily accessible for diving directly from the property. This just isn't possible at Caribbean Club due to the inland hillside location.