How can I get brine flavour into turkey?
Many aromatic compounds are oil soluble, or need to be heated to really come out and 'open up.' Since brines I use are all water based, I've had some luck with heating, even briefly boiling dried spice components first, then cooling, adding the other ingredients, then using. Especially, don't boil vinegar or alcohol components, as they will lose potency.

Anyway, I find brines to have a tough job imparting too much of a distinct flavor, so consider straining some of this out of your brine and using it to make a gravy or pan sauce to accompany the roast bird, the flavors will then be further accentuated.