This mystery wine(us6.campaign-archive.com) is Yalumba Old Bush Vine Grenache 2016(winestar.com.au)
If using the AmEx WineStar offer, buy a $150 gift voucher(winestar.com.au) first to receive $50 credit back, then pay for the wine with that voucher
For those with multiple offers/cards, consider Philipponnat Clos des Goisses 1992/1998/1999 $299(winestar.com.au) before credit back (2008: $435 elsewhere)(francesoirwineselections.com.au)
Clos des Goisses was the first single-vineyard grande marque Champagne(bloomberg.com), a more recent famously expensive example being Krug Clos d'Ambonnay
The 1992 is my favourite Clos des Goisses vintage (96pts)(champagnist.com) and a towering masterpiece (97pts)(vinous.com)
Champagne Seeks to Discover Itself in Single-Vineyard Wines(nytimes.com)
The single-vineyard champagnes reaching new highs(howtospendit.ft.com)
Nice wine, bargain price. The Amex credit is $50 for $150 spend (not $30). Cheers.