I have a hard time thinking of a question about Bash that is not on topic here.
It would also be on topic to ask about problems installing programming software like various IDE:s and such on Linux. But then again, such questions are ok regardless of the operating system.
But general Linux questions, like how to configure wireless networks or how to install graphic card drivers are not really on topic here. I guess one could say that a Linux question is ok whenever the corresponding question for Windows, MacOS or any other operating system also would be ok.
If Linux was an operating system solely used by programmers, then I'd guess it would be on topic, for the same reason that questions about programming tools in general are on topic. But Linux is widely used for lots of non-programming tasks.
Things I would consider an edge case is cli programs in general. After all, you can quite easily incorporate them in scripts.