This is a good question. In the version numbers article we talk mostly about the "Major.Minor.Revision.Build [Extra Status]" form of version numbers. However, wyBuild and wyUpdate are pretty liberal in how they handle version numbers.
The short answer: wyBuild and wyUpdate support the version number format you want to use. You can confirm this by typing the numbers in wyBuild. It automatically reorganizes them from oldest to newest:
[attachment=0]version.numbers.in.wybuild.png[/attachment]
The longer answer: the version algorithm we use treats the numbers as chunks of numbers, chunks of letters (e.g. words), and chunks of letters that are greek words (e.g. alpha, beta, release candidate). And the comparison happens one chunk at a time.