Q. Where can I find historical government & corporate bond yield, short term and long term?

You can try CEIC, either Global or Daily database or DataStream.

CEIC
After you have chosen the country of interest, the time series for the government & corporate bond yield can be found under the heading:  Interest and Foreign Exchange Rates [for Global database] or Government & Other Securities [for Daily database]

DataStream is available only from the terminals at Investment & Data Studio.  You can only launch DataStream from EIKON. 

DataStream
Click Time Series Request
Click Series Selection, choose Bond Indices & CDS, use the Explorer to choose the wanted series.
Click Datatype Mnemonic Picker, search for yield.
Choose the appropriate time period
Change the Freq if necessary
Submit your request