In your batch, in the first line you hand over control permanently to testrunner.bat. Control will never come back. In a batch if you want to run another batch and get control back, you use the CALL statement.
CALL "C:\Program Files\eviware\soapUI-3.6.1\bin\testrunner.bat" -s"TestSuiteName1" -r -a -j -fC:\Dev\reports -I C:\TestSuites\ProjectName1-soapui-project.xml > ProjectName1.txt
CALL "C:\Program Files\eviware\soapUI-3.6.1\bin\testrunner.bat" -s"TestSuiteName2" -r -a -j -fC:\Dev\reports -I C:\TestSuites\ProjectName2-soapui-project.xml > ProjectName2.txt