You cannot use wildcards for input files, but you can specify several test libraries on the command line:
/nologo /noshadow /framework:net-4.0 /xml:.\test\TestResults.xml .\test\SomeLib1.Test.dll .\test\SomeLib2.Test.dll .\test\SomeLib3.Test.dll
From the official documentation :
(DLL .exe), , NUnit. , :
NUnit (.nunit)
Visual Studio (.sln)
Visual Studio (.csproj,.vbproj,.csproj)
UPDATE
:
for /f %%f in ('dir .\test\ /b /s *.Test.dll') do nunit-console /nologo /noshadow /framework:net-4.0 /xml:.\test\TestResults.xml "%%f"
dir .\test\, *.Test.dll. (nunit-console) .