From the IEDC:

We organized shuttle from the airport Brnik (Ljubljana) to Bled on Wednesday, August 31. There are 3 options: at 11.30am, 1.30pm and 3.30pm and the price is 15€ per person that should be paid directly to the driver in cash or by credit card. Should you decide to take the shuttle, please send an e-mail with your preferred timing to: bled.taxi@gmail.com. If you arrive earlier or later and would like to arrange taxi from the airport, you can send an e-mail to bled.taxi@gmail.com and arrange it directly for the price of 45€/car (up to 3 people).

On Sunday, September 4 we will organize shuttle from Bled (IEDC parking lot) to the airport Brnik (Ljubljana). . There are 3 options: at 1.00pm, 3.00pm and 5.00pm and the price is 15€ per person that should be paid directly to the driver in cash or by credit card. Should you decide to take the shuttle, please send an e-mail with your preferred timing to: bled.taxi@gmail.com. If you would like to arrange taxi at any other time, you can send an e-mail to bled.taxi@gmail.com and arrange it directly for the price of 45€/car (up to 3 people).

Other alternatives are also available. See  http://www.zup-prevozi.eu/en/destinations/slovenija/taxi-transfer-ljubljana-airport-bled.html (You will need to cut and paste into your browser).