Is this expected behavior? Or is there a setting I'm missing or different
workflow I should follow in order to get textmate to remember what should
visible in my project?
Yes, this is expected behavior. It rescans the directories and adds files
whenever you open the project or command+tab back to TextMate*.
The way to change which files are discovered is to right click on the root
folder and choose "Show Information..." (or select the folder and hit
command+i). Where it says "Recursively Include Contents Matching..." you
can define "regular expressions" to include/exclude files and folders. I'm
not sure which syntax that box is using for the patterns but exclamation
point (!) acts as negation so you can easily exclude stuff from your
*You can use the plugin ReMate to disable this behavior if you don't want to
exclude the files but rescanning them is slow.
Hope that helps! Enjoy using TextMate! :)