From Webster's Revised Unabridged Dictionary;

reputed
adj : commonly put forth or accepted as true on inconclusive
grounds; "the foundling's putative father"; "the
reputed (or purported) author of the book"; "the
supposed date of birth" [syn: putative, purported, reputed, supposed]

reputable
adj : having a good reputation; "a reputable business"; "a
reputable scientist"; "a reputable wine" [ant: disreputable]

Two different words with two different meanings. You can't substitute one for the other. Also, "well reputed" doesn't make any sense.