Try checking where svn was installed (probably usr/local/ something) and see if that is in your path (env) will have to edit the rc/profile file for your shell to add it most likely
Most likely /usr/local/bin
instead of typing: $ svn something
you can type
$ /usr/local/bin/svn something
To see if that's where it is.
You can then edit your ~/.bashrc or ~/.bash_profile in order to add / usr/local/bin to your path by adding this to ~/.bashrc:
export PATH="/usr/local/bin:$PATH"
Save that, open a new terminal and it should work with just "svn something"
Hope that helps, -steve