Odoo views and reports are built on top of the bootstrap framework and use its grid system. Please learn about the bootstrap grid system and then use the appropriate classes by inheriting the corresponding QWeb view.

Idea (without knowing your xml-Code to identify and manipulate the proper div element):

<xpath expr="//address[@t-field='o.partner_id']/.." position="attributes">
                <attribute name="class">col-xs-5 col-xs-offset-7</attribute>
            </xpath>

This should give you the direction.