FILTER doesn't support wildcards, no. You need to do something like:
=COUNT(FILTER(B:B,B:B=223,SEARCH("herp",C:C)))
or
=COUNT(FILTER(B:B,B:B=223,REGEXMATCH(C:C,"herp")))
Alternatively, in the new version of Sheets, COUNTIFS is supported:
=COUNTIFS(B:B,223,C:C,"*herp*")