Yes it does. All premiers get more economy saver seats, and Platinum and 1K get more first/business saver seats. (From united.com)
Premier members also have better access to Saver Awards in United Economy®. Additionally, Premier Platinum and Premier 1K® members have better access to Saver Awards in United Business®, United BusinessFirst®, and United First® on 2-cabin aircraft. This benefit is also available for Saver Awards in United First and United Global FirstSM on 3-cabin aircraft until January 31, 2013. To get the best award search results, Premier members should sign in to united.com with their MileagePlus® number and PIN when searching for travel awards.
The only way to book this from your account would be to get platinum or 1K status, or just wait and see if United opens up more saver seats for everyone. Otherwise, you'd have to use your co-worker's miles somehow. Maybe pay them back some other way or transfer miles in the future when you can?
(Actually, I'm not sure if you can even book awards for others using the 'extra' saver award seats. I've only booked them for myself, not others.)