R/S chirality question
According to the Cahn–Ingold–Prelog priority rules, a double bond considered as ($\ce{CCX}$), where $\ce{X}$ depends on the substitution on the double bond. In your case, $\ce{X}$ is hydrogen ($\ce{H}$). Thus, I arranged the priority as depicted in following diagram (chiral carbon in consideration is marked with asterisk):



Hydrogen is the least priority group on the chiral carbon. Among other three groups, the bridgehead carbon is a $\ce{-CH2 -}$ group, hence can be marked as ($\ce{CHH}$) on priority checking. The final two groups can be marked as ($\ce{CCH}$). I used red and blue color on one group (methine on the ring), and black on the other (double bond) to distinguish these two group. Since both has identical substitutions on first carbon, we need to moved to second carbon. On double bond, it is again ($\ce{CCH}$), but bothe red and blue carbon give ($\ce{CHH}$) priority checking. Thus, double bond has the highest priority as indicated. Therefore, assignment for this chiral center is ($S$)- as given in chemspider website.