I'm not sure if I understand what you are doing with Bamboo. However you can get the project path this way in a Groovy script.
def groovyUtils = new com.eviware.soapui.support.GroovyUtils(context)
def projectPath = groovyUtils.projectPath
I found a link in ReadyAPI documentation (2.2) about datasource that might help. Hope this link below works. See section 3.1
https://www.soapui.org/scripting-properties/tips-tricks.html
I use 2.2 for now and I create a folder where I store any project's xml along with the keystore in that folder. Then I can refer to the ksystore password and ksystore from a groovy script using the relative path. I can launch test runner from linux using the command
/usr/local/SmartBear/ReadyAPI-2.0.0/bin/testrunner.sh
and one of my arguments is -i app.xml (I think that is my application).
This stuff is important to me as well since I need to do automatic scripts from any new folder. Just have to refer to absolute path of the readyAPI testrunner.sh