There is no bounding box like Illustrator because text are same as SKETCH, think more like CAD system instead of typesetting app.
You will need to create your own bounding box, yes its a tedious process and no quick way to wrap text, you will need to do it the manual way.
If you wanted to do one as a test try this method, there is more tutorials if you search wrap text.
If you got a lot text wrapping I would skip shapr3d, it just wastes your time but if you got some time to kill on iPad another story! I would just go with software that has text wrapping you can always import back to Shapr.