This should already be fixed, but if it wanst, the only way to make what you want would be like this.
.Grass. (12) "Spruce twig" [effort:2] [phys:stance,one-armed] *COMMON* /90/
{[TERRAIN:grove open_mire spruce_mire]} (any terrain that you want)
{[NEARBY_TILE:thicket]} +'Be near a thicket'
[NAME:Grass]
[TILEGFX:it-grss]
[TYPE:plant]
[WEIGHT:4.0]
That will make the game check the tile you need to be near and the terrain. In this code example you can only get grass on Groves, Open mires and Spruce mires while standing next to the tile named thicket. Hope it helps