As of this writing, the current wxWidgets API does not supply an interface to enumerate the tools in a toolbar if the tool IDs are not known in advance. A ticket suggesting this feature has been posted in the tracker. In the meantime, this recipe describes techniques that attempt to elicit this information using the existing APIs.
A Simple Approach for a Simple Toolbar
If you have a simple horizontal tool bar with exactly one row and evenly-spaced tools and no spacers, the following code snippet appears to work to retrieve the tools.
If you end up building on this to handle some of the aforementioned limitations, please consider updating this Wiki.