Welcome and congratulations on your new bunnies. Very cute! They look really happy in their new home. And it's nice and big, which is definitely something you'll need when your new zealand is full grown
Just a word of caution. It really would be best to separate them when they are 12 weeks old. It's hard to break them up, I know. I hated separating my babies too, as they were so happy being together, but if your girl rabbit were to get pregnant at that young age, it could potentially be fatal, as she wouldn't be fully mature yet, and that can cause complications. Also just leaving a male rabbit in with the female all the time, can also lead to problems like him mounting her at the wrong end, and her getting annoyed and bitting his genitals, and also female rabbits have two uterine horns and can get pregnant in both at the same time, which can also cause problems for them and even be dangerous to them as well. If you intend to breed, it's best to wait til she is mature at 6 mo. old. Since they are both still young, you have a few more weeks to think about it before it becomes an issue, but if you see him trying to mount her, that would be a good time to finally separate them til he is old enough to get neutered, if that's what you are planning to do.
With regards to their diet, grass hay is really good for their teeth and digestive systems. So eating lots of hay will help keep the sharp points on their teeth worn down. I prefer to feed my babies grass hay instead of alfalfa. Rabbits can get picky about their hay later on when you try to switch from alfalfa hay to timothy, plus too much alfalfa can cause digestive problems for some rabbits, especially if introduced into the diet too quickly. And if you are already feeding a plain unlimited (or almost unlimited) alfalfa pellet, then having alfalfa hay as well isn't really needed.
Not all rabbits like to chew on wood or branches. I have a few that will chew on just about anything, and others that are really picky and only like certain wood of certain thicknesses. I offer dried pine chew blocks, apple branches, and willow branches to my rabbits. Some like the willow and some like the apple better, some of them don't even touch their pine blocks. Just experiment with different rabbit safe woods, to see if there is one that yours prefer. And since they are still babies, it might just be that they aren't used to being able to chew on different things, and they may start doing it more as they get used to their new home and as they get older (so watch out for those power cords
).
It looks like you've already started veggies. Usually it's best to wait til they are 12 weeks, but if they aren't having any soft poops from eating them at this point, then you are probably ok to continue feeding them. Usuallly it's best to introduce new veggies, one at a time starting with small amounts and gradually increasing, to minimize the chances of digestive upset and soft poop. It's also good to limit sweet treats like fruit and carrots, to just a little bit each day, so that the gut flora isn't upset, which can cause serious digestive problems. Here's some veggie lists and diet info if you want to take a look at them.
http://www.3bunnies.org/feeding.htm#top
http://www.rabbit.org/care/veggies.html
http://www.rabbit.org/faq/sections/diet.html
Rabbits can really be wonderful pets. They definitely have their challenges, but when they give you bunny kisses, and when you see your first binky, it makes it all worth it. I hope you enjoy it as much as we all do