You cannot do this on the phone. Any contacts created on the phone that were added to one Gmail account, cannot easily be "copied" to the other Gmail account, especially not in-bulk.
You can however, do this quite easily on Gmail's web site:
- On your computer log into your Gmail account that has your latest contacts, and click on "Contacts" link.
- On the upper-right side click the "Export" link, select "Everyone (All Contacts)" and "Google CSV format" options, and click the "Export" button.
- When prompted, save the "google.csv" file somewhere on your computer (e.g. C:\ drive.)
- Log off your Gmail account, and log into your second Gmail account.
- Go to Contacts, click on the "Import" link, click on "Choose File" button, browse to your C:\ drive (or wherever you saved the file in step 3,) select the "google.csv" file, click Open, and finally click the "Import" button. You may also choose to add these new contacts to an existing group, or create a new one.
After a few minutes, these contacts should sync to your phone under the 2nd Gmail account.