(SMH) - AGL Energy chairman Jerry Maycock may find some of the wines he quaffs from the Hunter Valley have a touch of bitterness, malice and even a hint of sulphur. The clash between the who's who of the Hunter Valley wine industry and the gas and electricity company shows no signs of abating. Pushing on with the fight taken up by the late Macquarie winemaking chairman David Clarke (who was part of a protest outside AGL's 2010 annual meeting), an alliance of winemakers including Brian McGuigan, Max Drayton and Jay Tulloch has presented a ''white paper'' to the NSW government urging the creation of an ''exclusion zone'' to keep coal seam gas activity well away from the winemaking region.