First Interstate Bancorp's bonds were battered in the secondary market following the bank's announcement of a large loan loss provision and a cut in its dividend. The Los Angeles bank's 8.65% subordinated capital notes due in 1999 were trading at a yield 225 basis points over Treasuries; on Friday the rate was 195 basis points over Treasuries. Bonds of other California banks fared only slightly better. BankAmerica Corp.'s 9.5% subordinated notes due in 2001 were trading 140 basis points over, compared with a 130-basis-point spread Friday. And Security Pacific Corp.'s 11% subordinated debentures due in 2001 were trading 260 basis points over Treasuries, up 15 basis points from their level of 245 basis points over Friday.