Basically, the layout in HTML for a table in BibWord is:
class="MsoBibliograpy">text first column</p>
class="MsoBibliograpy">text second column</p>
The halign and valign parameters in BibWord are for the table cell properties. They only indirectly affect the text within a cell. To set the text alignment within a cell the MsoBibliography style (shown in Word as a localized version of the word 'Bibliography')
should be used.
If your bibliography is not in the 'Bibliography' style, then something is wrong.
Which style (or BibWord version) are you using?
What happens if you switch the reference style to APA (the one available in Word by default)? Is the style of the bibliography still 'Normal'? Or is it 'Bibliography' now?