Since he owns the business, he can choose not to put up decorations, and he can also choose to tell you to keep your religious teachings out of the workplace. You need to comply with that. It's not a problem anyway. If you want to teach those kids about Jesus, your best way to do that is to be like Jesus in the way you are with them. That's more effective than lecturing anyway.

Concerning holidays, I have a Jehovah's Witness friend who said he doesn't celebrate Christmas, but invited me to intend "Our church's celebration of the birth of Jesus Christ". I was like "Isn't that Christmas?" He replied, "No, we don't celebrate Christmas, just the birth of Christ". So the JWs are really rejecting is with the commercialized Christmas that we are all suckers for in modern day. Also, thanksgiving uses pagan symbols in its celebration (ie. the horn of plenty), and Easter was originally an ancient Roman holiday devoted to Ishtar, the god of fertility. I have no problem with JWs for not celebrating these holidays. I am not JW, and I disagree with a lot of their key doctrines, but I personally do not celebrate these holidays either.

Biblically speaking, we are not commanded to celebrate the birth of Christ, but if we do, we should do so on Yom Kippur, as that is around the time of year when Jesus would have been born, and also Jesus is the prophetic fulfillment of that Jewish festival, which literally means "Day of Atonement". Also, it is inappropriate to celebrate the resurrection of Christ on Easter, because it is a pagan holiday. In fact, Jesus died on the eve of Passover. Look at a calendar - Passover and Good Friday NEVER coincide. Constantine designed it that way so that Christianity would be removed from its Jewish roots (and he wasn't even a Christian). So if you want to celebrate the death and resurrection of Christ, do so on Passover and three days after. That's what I do.

Sorry for the rant. This just happens to be one of my favorite subjects. :)

Blessings,
Hikaru