In general, the 13f set from Thomson does not have bond holdings, but this does not mean that 13f institutions never filed any of their bond holdings.
From the SEC website: Generally, the list includes exchange-traded (e.g., NYSE, AMEX) or NASDAQ-quoted stocks, equity options and warrants, shares of closed-end investment companies, and certain convertible debt securities. Shares of open-end investment companies, i.e., mutual funds, are not included and, therefore, should not be listed on Form 13F. Shares of exchange-traded funds ("ETFs"), however, are on the Official List and should be reported. (source: https://www.sec.gov/divisions/investment/13ffaq.htm refer to question 7 )
For more, see the Thomson Financial manual we posted that discusses the holdings data and also see the SEC website to see the 13f requirements: http://www.sec.gov/about/forms/secformsalpha.htm
For the list of current securities for which holdings must be reported: http://www.sec.gov/divisions/investment/13flists.htm