Well it seems everytime I finally break down and post to Laracasts forum. I end up finding my own solution.
So I kept trying to use DB::raw without success, but wrapping it in a DB::select does the job.
Here is my working query for Laravel DB syntax
DB::select(DB::raw('SELECT id,company_name, company_code, company_contact_name, company_contact_email, company_contact_phone, (SELECT COUNT(id) FROM riders WHERE company_id = companies.id) as ridercount FROM companies'));