When configuring the bash on OSX via ~/.profile it seems to completely ignore it as soon as ~/.bash_profile exists. If this is correct and expected behavior, should I add my extra configuration stuff to ~/.bash_profile as well or use it instead of ~/.profile?
Thanks in advance.
It's expected behaviour. See here
When bash is invoked as an interactive login shell, or as a non-interactive shell with the --login option, it first reads and executes commands from the file /etc/profile, if that file exists. After reading that file, it looks for ~/.bash_profile, ~/.bash_login, and ~/.profile, in that order, and reads and executes commands from the first one that exists and is readable.
So only the first readable one counts.
As for which you should use, it's up to you - unless there are corporate policies or something else that creates a specific one, or relies on a specific one existing.