There are two ways you can link an object in Smarts SAM to a Service offering:
Method 1: Using the GUI
Method 2: Using <BASEDIR>/SAM/smarts/bin/dmctl
./dmctl -s <SAM Domain> put ServiceOffering::SRVO-<Service offering name::ConsistsOf <Class::Instance> <Class::Instance> <Class::Instance>
Repeat <Class::Instance> as many times as you need to in order to get all the Objects linked.