Is BLE 4.1 backwards compatible to BLE 4.0 ? Can a phone with bluetooth 4.0 talk with a mote with BLE4.1?
Got this answer from TI E2E forum. 

As per the Bluetooth SPEC, mote with BLE 4.1 should be backward compatible with Bluetooth 4.0. But you should keep in mind that you will not be able to take advantage of BLE 4.1 features. Mote will be as good as an Bluetooth 4.0 device. 

Again it also depends on whether the mote device wants to go ahead with a BLE Connection with an older device. Because even if the SPEC says that 4.1 device is backward compatible, it goes to the manufacturer to decide whether they want to go ahead with an backward device.