You know I did that and while my computer sees both my Comixolgy account and the Marvel comic code that I redeemed, both my Fire and my ipod sees only my Comixology stuff and not the Marvel.
Unless it takes time for them to all sync up? It took me forever to get all the devices with the proper accounts and it was still an epic fail.
I can tell you that reading the Marvel comic with the Marvel app on my iPod was horrible, not easy like my Fire with the Comixology app.
EDIT: I had two comixology accounts (somehow?) and was logging in with the different one which was why it wasn't seeing everything I had. I dunno. Anyhow, the Fire comixology app doesn't still see the Marvel book at all but my iPod does (WTF?). The Fire sees the Marvel book as long as log onto the comixology
web page, not the
app that came with Fire even if I use the same log in which makes zero sense. This means I have to use the web controls to read it which I can tell you was horrible beyond measure. BUT if I log in to Comixology (correctly, lol) on my iPod, it sees all and the reader (which was not the web reader or the Marvel monstrosity) was actually pretty easy to read on. The moral of the story here kiddos, is that The Fire pretty much sucks, which I've known for some time now. You want to eRead Comics, you need an iPad or maybe some other android tablet, but not the Fire.