I really enjoy both Jiko and Boma. Boma is great when we have kids with us and I love that there is so much variety (we are very adventurous eaters). However, Boma is incredibly noisy.
Jiko's menu is much tamer. The food is good but the only adventurous items are the appetizers; the entrees are all pretty tame. However, the atmosphere here is much more adult, it will not be near as noisy or chaotic here.
For a honeymoon, I would definitely pick Jiko.