Just to play devils advocate, if you do a group you are locked in to their choices. With the driver, you have more choices and don't have to worry about a crowd. You can do research or We let the concierge choose for us and had a great variety of views and a really lovely spot for lunch. Dela ire Graff is really beautiful and might be a nice splurge for a honeymoon meal. Be sure to tell them you are on your honeymoon and ask for suggestions. That's their specialty.
We had to make really good use of time so in one day we went to stellenbosch 3 wineries incl
using a leisurely lunch and a drive to the cape point going up up both sides of the peninsula and a stop to see the penguins and we really didn't feel that rushed. Otoh robben island and table mountain alone took the better part of a day.
You will have a good time whatever you choose.