In my house I know that spaces like that have framing in them (and I suspect your how should too) and if you anchor attach to them you will be fine to mount a TV. It may not be solid wood but there is likely a stud next to each window, which will be more than enough to support a TV.
BTW "load bearing" usually means a wall carrying the weight (load) from something above it; as that is an exterior wall it is most certainly load bearing. A TV mount does not have to be placed on a load bearing wall the framing of any wall should be sufficient to support a TV . . .as long as it is attached properly.
I personally would be hesitant to mount a TV directly in front of 2 windows, but that is just personal preference and it just seems odd/an after thought. . . plus if you ever want to move it the drywall work and paint is a PIA.
Personally if I were you and I wanted to have my TV raised in that location, I would look into a stand like you have, but with a mounting post of the TV. As an example here is a link with a picture of what I am talking about
http://www.globalsources.com/si/AS/Yuefeng-Hardware/6008827264949/pdtl/Glass-TV-Stand/1046187204.htm