Do I understand you correctly that you want to charge 100€ shipping if the buyer buys only products from manufacturer 1 or 2? All other orders should not be allowed?
With the advanced plugin you can check the Manufacturers variable:
Name=Products of Manufacturers A and B; Manufacturers==list(123) OR Manufacturers==list(111) OR Manufacturers==list(111, 123); Shipping=100
The numbers 123 and 111 need to be replaced with the manufacturer IDs from the virtuemart backend.
It is some kind of hack, but it is supposed to work.
Note that a shipping plugin cannot display any text/warning unless it gives a shipping rate. So it is not possible for the plugin to print out a warning like "Sorry, Products from manufacturers A and B cannot be ordered together with other manufacturer's products".
For this, some core VirtueMart code files would need to be changed.