If the trees are inserted into a block shape by the rule file that is applied to that block shape, then no, I don't think there is a way you can get the positions of the trees in python.
If each tree is created from its own initial shape, then yes, you can use ce.getObjectsFrom() in python to get the shapes. Then, you could use ce.getVertices on each shape.
There are examples on the reference page for ce.getObjectsFrom() that show how to get different kinds of shapes. Maybe using ce.isShape and ce.withName would help.
Python Scripting Interface Reference