You can buy blue tooth transmitters and receivers for around $25. I have a BT transmitter hooked to my directv receiver via RCA connectors and transmit to my bose BT speakers.  Works awesome. Can also use my iPhone via BT to connect to bose system. You could use the BT transmitter with your laptop via the audio jack. BT sounds way better than modulated fm transmitters.  My bose BT speaker also has a rechargeable battery built in so I can take it anywhere in the house and even on the patio or garage.
Here is what I got. 
Blue tooth transmitterAnd 
Bose