Today, pax-exam basically creates a bundle containing all. It would be great in configuration to be able to bootstrap other bundles used in the test (better leverage tinybundle for instance or wrap).
Can you explain a little bit more? Its true that pax-exam puts all TESTS into one bundle, but you can install/create as much other independently if you like, you can even install them dynamical by injecting the bundle-context into your test and use pax-url, file protocols and yes also tinybundles, the cm-module uses the approach to create a bundle on-the-fly that tracks configurations for example and installs it next to the bundle probe.
I "workaround" by creating kind of "itest controller" deploying several bundles.