RAR/ACE/etc used continuous compression - all files were concatenated and compressed as if they were one single large file. Much like what is done with .tar.bz. Bzip on Windows did not do that, there was no equivalent of .tar.bz2 on Windows.

You can bzip2 -9 files in some source code directory and tar these .bz2 files. This would be more or less equivalent to creating ZIP archive with BWT compression method. Then you can compare result with tar-ing the same source directory and bzip2 -9 the resulting .tar.

Then you can compare.

The continuous mode in RAR was something back then, exactly because RAR had long LZ77 window and compressed files as continuous stream.