Track a point & Camera movement without a good tracking object?

This looks more like a job for Mocha AE than Camera Tracking or Motion Tracking. Simply tracking the position, rotation, and scale of the area of the shot where to logo goes would probably give you enough information to apply to a null that could be used as a parent for a 2D text layer. Pick the frame where the logo would first start to appear, split the layer, pre-compose moving all attributes to the new comp, add an adjustment layer with a bunch of color correction to enhance the detail in the sky. You'll turn it off after the tracking is done.

Then run Mocha AE on the nested comp (pre-comp) and draw a spline on as much of the sky and horizon line as you can. You should then be able to set a couple of keyframes for the Surface and use that data to generate position, rotation, and scale keyframes for a null. Then all you need is to attach the text layer to the null and adjust the position. 

When you have completed your track - and it may take a bit of keyframing, and you get the Null to stick to the horizon, all you have to do is Parent the logo layer to the null and then position and scale it properly.

It would really help if I saw the shot, but I do this kind of thing all the time when Camera Tracking is not practical. I can't remember the time I tracked anything more complex than a single object with AE's motion tracker so that would not even be considered for this kind of shot.