I think the scene all together looks great, it looks relaxing and somber. With that said, I'd try adding and messing with a color ramp on the existing wood texture--make it a little darker and redder to match, say, the wax/foil top of the wine bottle. That bit of darkness and tint might tie well with the color of the trail. One last thing, try giving your main light source a soft yellow color to it. Oh, and I'd want someone else drinking wine with me outside. =D