Hi,
HikaShop 3.0 will indeed include a bundle feature.
However, it won't help in that case since usually, when you have a bundle, you have the price set in the bundle and thus, you only have the tax rate of that bundle product price.
It would require adding some code to the system to calculate the price of the bundle dynamically when not specified in the bundle. That's potentially something we will be able to add in the future if people need it (and could be done with a custom price override plugin if necessary until then)