It will probably work. In theory, the two groups should keep to themselves and not mix. Problems with tiger barbs normally arise when they are not kept in a school. Silvertips are generally considered to be more aggressive then most tetras so should be able to look after themselves.
Hi, I just put my silvertips in with the tigers and thought i would let you know what happened, well - the tiger barbs attacked the silvertip tetras big time , the silvertips on the fins seem to attract the barbs, maybe they thought it was food, anyway i had to take them back out, i think the mix would have worked if they were in a tank 3 x bigger than mine. lesson learnt