.cvswrappers are not used by MacCVSClient.

Instead, the (import) Translators and Ignore Filters preferences are there to define a set of rules how to treat files when importing and adding (in general getting things into a repository). Export Translators are the counterpart for settings regarding getting files out of a repository).

When importing or adding, you will see the import/add preview window where you can get a glimpse at what an add or import operation would do to your files — how they would be treated. See also: CVS Add and Storage Formats.