thanks for the answer.
As always, I like to post a code sniplet . so here is a sample code to perform the task:
(to find the content of getRepositoryWorkspace method, look at my older posts)
<code>
public void someMethod(ITeamRepository repo, IProgressMonitor monitor)
{
            IWorkspaceConnection wrkspace =  getRepositoryWorkspace(repo,rtcWorkspaceName,IWorkspaceSearchCriteria.WORKSPACES, monitor);
            String masterStreamName = ....;
            IWorkspaceConnection masterStream = getRepositoryWorkspace(repo,masterStreamName,IWorkspaceSearchCriteria.STREAMS,monitor);
...
compareAndAddMissingComponents(masterStream,wrkspace,monitor);
...
}


/**
     * A method that takes an old workspace and verifies its in sync with all the new component in some stream.
     * If the stream has been updated recently with new RTC components, the method
     * will update the workspace to include the new components too.
     * @param baseStream
     * @param oldWorkspace
     * @param monitor
     */
    public  void compareAndAddMissingComponents(IWorkspaceConnection baseStream, IWorkspaceConnection oldWorkspace,IProgressMonitor monitor)
    {
        Collection<? extends ICurrentComponentInfo> streamComponents = baseStream.getComponentsInfo();
        Collection<? extends ICurrentComponentInfo> workspaceComponents = oldWorkspace.getComponentsInfo();
        if (streamComponents != null && workspaceComponents != null) {
            if (streamComponents.size() != workspaceComponents.size()) {
                for (ICurrentComponentInfo newComponents : streamComponents) {
                    if (!workspaceComponents.contains(newComponents)) {
                        UUID uuid = newComponents.getComponent().getItemId();
                        WorkspaceMissingDialog dialog = new WorkspaceMissingDialog(newComponents,oldWorkspace );
                        Display.getDefault().syncExec(dialog);
                        System.out.println(oldWorkspace.getName() + " is missing a new component:"+
                        uuid+ ". should I add to "+oldWorkspace.getName());
                    }
                }
            }
        }
    }

class WorkspaceMissingDialog implements Runnable
    {
        ICurrentComponentInfo newComponent = null;
        IWorkspaceConnection oldWorkspace = null;
        public WorkspaceMissingDialog(ICurrentComponentInfo NewComponents,IWorkspaceConnection OldWorkspace)
        {
            newComponent = NewComponents;
            oldWorkspace  = OldWorkspace;
        }

        @Override
        public void run() {
          final String oldWorkspaceName =  oldWorkspace.getName();
            UUID uuid = newComponent.getComponent().getItemId();
            String message= oldWorkspaceName + " workspace is mising a new component named:"+uuid+
                    ". should I update the workspace definitions ?";
            approvedToAppendToOldWorkspace = MessageDialog.openConfirm(shell, "New Workspace?", message);
            if (approvedToAppendToOldWorkspace) {
                try {
                    IProgressMonitor monitor = null;
                    IComponentOp addOperatrion = oldWorkspace.componentOpFactory().addComponent(newComponent.getComponent(), false);
                    List operationList = new ArrayList();
                    operationList.add(addOperatrion);
                    oldWorkspace.applyComponentOperations(operationList, monitor);
                } catch (TeamRepositoryException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
        }
    }
</code>