I seem to recall somebody trying something similar to this recipe recently...
Heather mead post
Whole Hive Mead
I would think that you would want to loose the chunky bits by the time it comes to bottling. You could do that with the heather, nothing wrong with adding the flavourings in a "teabag" of sorts--just make sure there's enough room in the bag for the liquid to flow through.
I was eyeing the heather tips as well, when I shopping for other herbs for a mead...keep us posted on what you end up with, flavour wise.
There is one secret ingredient that makes anything better......time.
Primary: House Cider; Carrot Wine. Anchorage Brewing Dregs Cider
Secondary: Rhubarb Wine, House Cider
Tertiary (or higher):
Drinking: House Cider, Cherry Cyser, Belgian Walnut Graff, Rhubarb Wine