Assuming they're actual Word bookmarks:
Sub SendBkMksToPDFs()
Application.ScreenUpdating = False
Dim DocSrc As Document, DocTgt As Document, StrPth As String, BkMk As Bookmark
Set DocSrc = ActiveDocument
With DocSrc
StrPth = .Path & "\"
For Each BkMk In .Bookmarks
Set DocTgt = Documents.Add(Visible:=False)
With DocTgt
.Range.FormattedText = BkMk.Range.FormattedText
.SaveAs2 FileName:=StrPth & BkMk.Name & ".pdf", Fileformat:=wdFormatPDF, AddToRecentFiles:=False
.Close False
End With
Next
End With
Set DocTgt = Nothing: Set DocSrc = Nothing
Application.ScreenUpdating = True
End Sub