Management cannot be relational oriented, but an organization can.
Let me explain the concept...
There are many departments within an organization, there is the finance department, the IT department, the HR department, etc... Generally, any action taken by any department affects the other departments as well. For example, let's say that the finance department decides to reduce the expenses this year, this will naturally affect other departments.
Now in normal organizations, these "interdependencies" between departments are not handled properly, but in relational oriented organizations, any change done in any department is well studied and contingencies/plans are usually put in place by all the other departments (either to minimize the negative effects of the change or to benefit from the change) before that change takes effect.
Obviously, project managers are affected positively by this organization style, because they won't just be "hit" with news, they will know about what will happen in other departments in advance, and they will have enough time to plan if needs be. For example, in case the finance department decides to cut the internal expenses a bit, then the project manager needs to re-negotiate the scope of the internal project he's currently working on, maybe cutting some features here and there.