Picture this. Your swimming around a giant tank. Your scooped out along with fifty of your friends. Your put on an airplane(the cargo hold, not the comfy cabin), then onto a UPS or Mail truck. You arrive at new tank at the pet store. You float around for awhile, and the bag is cut open and you are dumped into this new tank. Just as you are getting comfortable in your new tank, and meeting your new neighbors, you are netted out again.
After all of that, do you really think a short ride on a motorcycle will stress the fish any more? I've bought fish on my Harley, and they lived. I asked the fish what they thought of the ride, but they never answered. I think the fish will be fine. The fact that your worried, leads me to believe that you will make the fish very comfortable once they are in your home.