I don't have a lot of experience, but I have watched the tiger barbs and albinos at various pet stores as they are by far my favorite fish. I too hope to get several of both varieties!
I too had been curious about that question, and had asked some reps at my local pet stores. Both from their experience and from my observation, it seems that it depends on the individual fish. I noticed some tigers and albinos cruising around together, but I also noticed that for the most part, all the tigers were together, and the albinos had formed their own separate group.
Maybe if you only had 7 total, they would 'shoal' together just fine, maybe they only separate if you have large amounts of each?