Looks good to me. By the time it's mixed in you'll have a job seeing it in the mix.
I wish I could find stuff this small. The best I can do is mini nuggets, twice or three times your size.

The same site carries beautiful pine bark, too.
But holy cow, very pricey!! I would have spent $400 vs the $40 or so I have spent on bark repotting everything!

Grace

Here is a link that might be useful: Small pine bark

I've also had trouble getting the pine bark fines locally (all the Home Depot/landscaping stores seem to have is pine bark mulch that's 1/3 sapwood and 1/3 dust, which doesn't seem ideal). I ended up getting a large bag of Repti Bark at Petsmart. At $20 for 24 quarts, it's more expensive than the mulch, but seems to be useable as-is (at least for the 5-1-1 mix). I think it's similar in size to the one you linked, or even a little bigger, so I think what you found there would work.

I'm still hoping to find the right brand of Pine Bark Mulch (any tips on locating near Boston? Anyone :) ?), but this is working for now.

Good luck!