I has been facing the same problem. All of the literature contain nice and simple node names, but any of them could be used in (current version) of Quartus Prime.
I have tried to do many experiments but I am still not sure about the proper solution.
By the way, as far as You would like to get know the necesary node names for timing constains into SDC files, the best way is to use derive_ppl_clocks command (eg. in a copy of Your SDC file or from TLC command line in TimeQuest) and observe sources and targets of derived clocks in TimeQuest Clock report or Clock Tree report. This is the most universial manner of getting the information for any setup of PLL IP core. Then You will be able to write down the right names to commands in Yours SDC files.
Please, do not panic, the node names are quite complicated and, moreover, some clocks are diverd inside the PLL! A good strategy is also to look at Technology Map Viewer to the instance of PLL compoment.
I hope this message help You a bit. Best wishes.