No, you can't do this "in bash". You can, with the right other tools,
request that the window be raised to the top but the window manager may (or
may not) honor that request.
Before we get to that though stacking order is generally bottom-to-top
so if you start the program you want on top last it should, generally, end
up on top in the end.
To request that a window be made on top you can use something like
xdotool and similar programs.