If the TV has a component video input you should use that. Better picture than composite.
You could buy an AV to HDMI converter but it makes more sense to buy a disc player (DVD or BD) that has HDMI out. It will have a better picture.
You can still use the Bose for CD playback and as a sound system for the TV connecting it to the TV optical audio output. Check the TV manual on how to use it. You may need to turn it on and turn the TV speakers off.