Hi Tim,
I think this might actually be "physiological leaf roll" as it does not resemble the virus infections I have worked with in tomato or seen through my research. The leaves in the second picture of the whole plant look to be normal color. The leaf in the first picture might just be senescent if it is an older leaf. This happens with older leaves of tomato (the ones near the bottom of the stem) as it grows taller and puts resources into the newer leaves. The yellowing you show in the picture is not typical of a virus. Physiological leaf roll can be caused by excesses of moisture or nitrogen. If your pot is not draining properly, that could be the problem. The plant looks a bit young to be putting on flowers yet, but if you are concerned about lack of flowering you can increase the amount of phosphorus relative to nitrogen and it will encourage production of flowers.
+ 1 point for providing images almost 10 years ago.