Vicarious,
Nice looking serissa, how big is it? Also, please fill in the location on your profile, it makes it easier for others to give you advice when they know the climate that you are growing your tree.
First, if it is warm (>40 degrees F) put it outside, bonsai trees do better outside and very few people, with a lot of specialized equipment, can maintain a tree inside.
Second, the soil looks like potting soil, be careful not to overwater and maybe repot in the fall or next spring into some good bonsai soil. Search the forum and you will get many opinions on what good soil is, whichever you choose, just make sure it is well draining.
Third, the wire will be fine left on, watch for biting, then remove. I would maybe reposition some of the limbs into a lower position, especially the first one on the right. You could also nip the ends of the branches so you will start to get some ramification. If you wait until after the flowering period, you will be waiting a long time, serissa bloom all through spring, summer, and fall, if they are happy, so prune whenever you are ready.
Enjoy, serissa are fun.
John