Python 2, 90 * 0.75 = 67.5

n=input();b=1while b<n: b+=1;s="";c=k=n while k:s=`k%b`+s;c*=k%b<2;k/=b if c:print b,s

Pretty straightforward iterative approach.

Without the bonus, this is 73 bytes:

n=input();b=1while b<n: b+=1;c=k=n while k:c*=k%b<2;k/=b if c:print b