It's less of a problem in today's Linux monoculture, but I actually initially learned Perl and Tcl precisely because of subtle incompatibilities between systems for tools like sed and awk, not to mention utilities like ps and tar.
This may not count because it's not bash specifically or even Linux -> Linux, but one place you might run into this is running scripts between Linux and Mac/BSD.
In the past I've seen bad things happen because a script was written by someone on OSX that gets run on a Linux (GNU) based system.
Two common examples are the `sleep` and `sed` commands.
I'm not aware of any difference in bash between vendor distributions for which this is true.