In your vBulletin admincp browse to this page: Bulletin Options > vBulletin Options > Style & Language Settings
There is a setting in there (I think it's the last one on the page) that allows you to switch to the 'legacy' postbit layout. Once you turn that on all user information will be to the left of posts.
Please note that from now on you'll have to make changes to the postbit_legacy template, instead of the postbit template.