I forgot to mention few things:
at now I have tested the SDL with a 1280x720 16bpp/50hz hdmi display, and works fine. The board is BBBW.
I am using the 4.4.x with omaplfb module, and the libraries EGL/GLES2 from the sdk.
If I have time in the next week I should try with different resolution and color settings.
Running the tests in the test/ directory I got some numbers for the fps that are interesting for the BBB,
for example: testgles2 150/160fps , testsprite2 more 100fps, this without vsync,
Using the sdl_gl_setswapinterval(1) and the powerver.ini=libpvrPVR2D_FLIPWSEGL.so the vsync seems working and I get 50 fps.