I realize this is a really old, but I was googling and came across this thread. I received the spec sheet from Amoretti and Artisan Blueberry now shows a Brix of 74.5 +/- 3 Brix. However, the bottle shows a sugar content of 52 grams per 100 grams of flavoring.
Going back to the math, 184 grams or 6.5 ounces, you're looking at 184*52 = 95.68 grams of sugar.
From Google: Degrees Brix (symbol °Bx) is the sugar content of an aqueous solution. One degree Brix is 1 gram of sucrose in 100 grams of solution and represents the strength of the solution as percentage by mass. If the solution contains dissolved solids other than pure sucrose, then the °Bx only approximates the dissolved solid content. The °Bx is traditionally used in the wine, sugar, carbonated beverage, fruit juice, maple syrup and honey industries.