In order for the Fear the Walking Dead characters to show up in the Walking Dead comics, the Skybound/Image Comics company would need to license the characters from AMC.
If the characters can’t connect in The Walking Dead comics, there’s a good chance they won’t connect on the small screen, either.
The Fear the Walking Dead show, on the other hand, was developed for AMC with entirely original characters.
The Walking Dead show is based on Robert Kirkman’s wildly popular zombie apocalypse comic series, and most–although not all–of the characters are adapted directly from his stories.