Yes, plyometrics are the best way to increase speed and vertical leaps, because they help increase agility. Plyometrics help people work on fast muscle movements, and all the different movements involved in playing a sport. Plyometrics are a helpful tool in increasing athlete performance, along with actually practicing the sport itself.
I used to play basketball and I wanted to increase my vertical leap so I tried certain plyometric exercises and did increase my leap. Acceleration speed also increased and eventually I ended up being able to dunk 1 handed with a run up start. Only 5'11 also quick punches with might. MAGIC.