Sychronization in virtuel wire

So you got me wondering if I just got lucky with my RF remote control then:

I am using pin 10 as Slave Select with SPI to a MAX7221, I only made these statements for the receiver:

  // Initialise the Wireless Receiver IO and ISR
  // set Virtual Wire data input to Pin 9 from 11
  vw_set_rx_pin(9);  // found this in forum 25 Aug 09
  // set the Bits per sec 
  vw_setup(2000);
  // Start the receive PLL running
  vw_rx_start();

and only this for the transmitter, with D10 being used as a Column pin for a keypad, and D11/D13 not used.

 // Initialise the IO and ISR for VirtualWire
  vw_setup(4000);	                      // Bits per sec - had to double from 2000 with 8MHz 3.3V Pro-Mini