Well, the Samsung TV can register several devices and save them. You can then freely switch between both speakers but you won't be able to use both speakers at once.
If you connect the USB dongle to a PC though, most standard 10$ Bluetooth Dongles will allow 4 to 6 different Bluetooth devices connected at the same time (i.e: mouse, keyboard, speakers, etc...)
However, even on a PC, you'll have to chose which speaker to use if you connect two different ones.