added roughly 1.5 mL of fresh ground quinine bark powder, as per suggestion on the Kina aromatised wines page - bark chips were readily available in Australia from Austral herbs. Definitely balanced the sweetness of the Lillet blanc and added depth of flavour. Not noticeably bitter or overpowering, could potentially add a little more. After two days macerating in the fridge the flavour was increasing, so strained the quinine out using muslin.
Interestingly, I felt not. I tried leaving the powder longer in a fresh bottle but I found the quinine flavour only noticeable when I shook the bottle to mix it through again, otherwise it was effectively the unadulterated taste, even after a week or more. Interested to see if others agree.