Hi Scott Nice pic! I don't think you will have a problem. I've seen this quite often, and usually the problem is not running a jitter-bug over it quite enough to ensure the gravel, sand and cement all mix and flow together, although a dry (low slump) mix will often do the same thing. Bull floating will bring the cement up to the surface and make it look nice, but won't help you down in 'the mix'. For future reference, you can also do this by hand (as I used to have to do :-( ), using a hand jitter, but its a lot of work. Anyway, I don't think I'd worry too much about it.