Thanks for your question. We are currently working on the new version and we don't have the final image of what we will support. As you may know, Ionic and Bootstrap have many things in common but also it could create conflicts. It's not easy to support everything and there are many Bootstrap versions.
However, we will support main content format classes like text-left, right, center... text-success, danger etc... In order to discuss and improve all this topic I've created an issue. We should discuss the scope of Bootstrap and Fontawesome support.
Have a great day! Cheers!