I observed all of ds's VT sessions and did the practice every night.  In my untrained mind, it seemed very much like OT that focuses primarily on the visual system.  I am still not sure if I endorse VT - my son hated it, practice was a nightmare, and the benefits seemed to wear off over time.  
My son's LD school recommends forms of cognitive therapy that address these systems in a similar, but different way.  We have not participated, and again I am a bit skeptical.  But, there are number of believers out there that are much smarter than me!  I tend to be a bit conventional when it comes to treatment and try to focus on where will get the biggest bang for our buck.  For my guy, reading is the main issue, so I tend to focus more in this area.  
We've done OT and VT - but stopped at age 8.  I do think this is all related and various disciplines can help - it's hard to decide where to focus efforts and how to measure results and improvement!
Yes - we did some of the worksheets at home.  Tangrams are good too.  Puzzles, dot to dot etc.