Travel from bingling si to linxia by boat ??

Well, the boat trip from the temple to Linxia is impossible. For your plan, here is my suggestion as for the transportation:
Upon landing, take a taxi to Lanzhou West Bus Station. Take a coach to Liujiaxia (if using Yonglan Highway, only half an hour is needed). Then walk 10-15min to the dock to take a boat to the temple. Including the journey on boat for a round trip and visiting time there, 7-8h can be required. After that, take a taxi from Liujiaxia to Linxia within 50min or so. At Linxia South Bus Station, many buses are scheduled to Xiahe and I remember the last bus departs at 17:30 or so. Hope you can catch it!

If your timing is not enough in a day, it is best to stay in Linxia for a night and head for Xiahe in the next morning.