Reno:
First I would say no receptacles at the sitting area. Looking at that fine pic, I see no location on the 'face' to mount a receptacle. A carefully selected location, perhaps underneath the 'tabletop, or underneath the 'drawer' area, could serve as a GP 6-12.
Difficulty integrating a receptacle into the kitchen designer's island does not mean it's not required. There are other options, including floor-mount receptacles. Or changing the cabinet design. Aesthetics or difficulty in incorporation into a given design are N/A.
NEC sets no limit on the height of wall receptacles, only the spacing (6/12') so receptacles mounted high on the bar may be allowed to perform double-duty... so long as the room outside the kitchen was an eating area or other area permitted to share the 20A GFCI kitchen circuits.
