ONLY if the dealer can prove that what ever failed on your car was caused by the springs not being installed properly.
If your driver's window motor stops working, then you are fine because it had nothing to do with the springs...
If your wipers stoppped working because during the install process you had to remove them and put them back on, and you re-installed them wrong. Then you're wipers aren't covered by warranty.
Your suspension might not be covered anymore under warranty because a non-licensed mechanic did work on it. (If you're a licensed mechanic then your warranty is fine because you know what you're doing)... Actually most people know what they are doing if they are willing to install the springs themselves. But as far as toyota is concerned, Not a Toyota Employee, Not gonna cut it.
It's always good to make friends with guys in the service dept at dealers because then you get good deals.