We took our little ones to Boma for dinner and everyone loved it! The resort is beautiful and you can step out onto the veranda to see the animals. They also had some activities going on for kids -- little song and story -- we all participated and had a blast.
A possible downside is that it's obviously easier to just eat at Tusker House in AK if you're already there. You've got to get yourself over to AKL via bus to AK and then bus to AKL, or just drive separately.
Food and atmosphere were different, lovely and fun at Boma.
Hope you have a great trip!