I went to Domaine La Garrigue in Vacqueyras three years ago on a brief visit after tasting them and liking them at the biennual Découvertes du Vallée du Rhône trade tasting in the valley and wanting a few bottles to drink! Website is:
http://www.domaine-la-garrigue.fr/ though doesn't look like it's been recently updated.
The word "garrigue" in a tasting note does indeed imply the wild scrubland found in the Languedoc and Provence, which consists of broom, wild thyme, sometimes wild rosemary or lavender and no doubt other plants.
Garrigue is never specifically planted, I don't believe - it's simply the wild, natural vegetation of the area - it springs up after again after an area has been devastated by bush fires, for example.
BMcKenney wrote: .... it's traditional among the wine makers of those regions to report these herbal aromas in their wines
The French verb
to report as used here simply means to describe, I think.
I really think that finding this smell in the wines is similar to finding a smell of eucalyptus in certain Australian, Chilean (especially Maipo) and South African wines in areas where eucalyptus trees are widely grown. Some of it must get into the soil in some way.
Either that or it's simply auto-suggestion - I often find what I think of as a smell of
garrigue in Rhône, Languedoc or Provence reds.