I don't know of any product that can do that for sure, but
The Godfather has a LOT of functions it can perform to tags in many formats, and it's free. It may very well have the means to either convert tags (which would require re-padding the encoded files, though), or at least applying ID3 tags with the info from FLAC tags.
If this product doesn't do it, then I don't know what else might. Worth a try, though.
Edit: Rjamorim's probably right. I've been surprised by
foobar2000's capabilities many times, and I wouldn't be surprised if it can do tag conversions. But as I said, I think it would require re-padding the files to be able to apply the additional tag info. foobar2000 is free, as well.