These both are from the same clone of the Original Grandpere Vineyard the oldest Zin vineyard in California. Vino Noceto's Original Grandpere Vineyard is the real thing and Renwood's Grandmere was established from cuttings of the OGP.
I actually like the renwood zin better. Both wines are 2002 and about 15.5% alc. These are really very similar and seem to be the same clone. Both have the prune/ripe plum fruit character of this unique old vine zin. Unfortunately, VN is ruining its wines with too much new oak. You have to decant off the oak to get to the fruit of the Zin in VN's wines. Both are very low acid, but without a characteristic over ripe taste. It is hard to describe the acid.
Renwood's has more of the tannin finish, but both finish with slight tannin. Both are medium dry with no distinct sweetness, but not really dry.