Your prep work (r-maps in this case) being "Versatile" means that you can use the prep you've written down well with whatever context develops within the actual game.

Very non-versatile prep

The old school D&D scenario. A list of encounters, and how to string people along from scene A to scene B. When faced with a player that wants to exercise choice outside of the prescripted scenario, the GM has two options: use force to push them back into the limited set of choices, or go free-form. Because we're assuming that you want to avoid forcing people into a pre-set story, this sort of prep is very non-Versatile, you can only use it in one pre-set context, and once players diverge from it, it's awkward to swing them back in.

Fairly versatile prep

A list of Bangs without a Relationship Map, usually depending if people get intereasted in certain NP Cs or if they take certain decisions. This results in some good games and a lot of prep work going by the wayside simply because the situation in which a series of prepped Bangs would be appropriate simply never occured.

Extremely versatile prep

Relationship maps and Bangs. Versatile because:

1) It provides a strong network of activity -- you can pick up any r-mapped NPC and they'll have an involvement in the story.

2) There are near-infinite ways that you can express a daughter's conflicts with her father; this is far more adaptable than, say, a particular mystery the players have to solve: the players' characters could be involved with the father or daughter anywhere and for a myriad of reasons, but the mystery depends on players' characters being in a specific place and having very particular motivations.

Why say "Versatile" rather than "flexible"?

To most people, a "flexible" game can and usually does include abandoning your prep entirely and just going freeform. Therefore a "flexible" game is almost entirely dependent on a specific quality of a GM; that they are willing to let people go free-form.

By using "Versatile" as a definition of preparation, you're saying that you have solid gaming material that you're able to use in a wide variety of contexts, and therefore have little reason to abandon your prep work.

[1]