Short answer, no it won't bleed through. In any reasonable scenario of variables (combinations of paint/grout types etc), you should be totally fine. To start, grout once mixed isn't very absorbent. It's also rather viscous (thick), as are most household paints. For bleeding to occur it will happen through absorption, capillary action or some sort of dissolution. And that's where i realize this is getting wayyyy too science nerd heavy, even for the extended answer. So in summary go for it you'll be fine. If you're really worried about it though either let the paint dry first, or take some scotch tape around the tile edges to create a protective dam that is easily applied/removed.
I do not work at Home Depot you will have to call or visit them and go to the paint department I don't have an answer for you I'm sorry
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