If you're interested in Bootstrap integration, I recommend taking a look at the AsciiDoc Bootstrap integration by Laurent Laville.
To use this backend with Asciidoctor, you'd have to port it to the Asciidoctor backend system since it's (intentionally) different from AsciiDoc Python. (Otherwise, you'd have to use AsciiDoc Python). I think the backend is definitely worth porting.
The AsciiDoc Bootstrap integration takes a slightly different approach than the integration with Foundation. AsciiDoc Bootstrap customizes the HTML output generated by AsciiDoc Python so it conforms to the existing Bootstrap semantics. Foundation is a lower-level CSS framework and therefore it was possible to adapt Foundation styles to the standard HTML output. While you could take that approach with Bootstrap SASS, it's probably more productive to build on what Laurent has done.
Good luck!