Check the AAMC website for syllubus. They have broken down the subjects quite well. If I remember right, Alkene, Alkynes and Benzene are not there..... But EK goes into just enough detail into these topics so we can build up on the knowledge. Understanding the basics certainly helped me.
I wrote in August last year and stuck to the list on the AAMC site and got a 14 in the BS section and I did not do well in orgo in school cuz, well, I didn't like it.
If you're good at orgo, then it won't hurt to review that stuff. Otherwise, there's a lot you need to know for the test so don't waste your time studying what you won't need to know. Most of the orgo on my test was carboxylic acids and their derivatives .
The Kaplan orgo guide (I skipped the benzene chapter) was great for this!