Use dois grep s:
grep "GET" /home/tsec/prototype/logs/glastopf.log | grep -vF 141.8.83.213 | ...
Em man grep :
-F Match using fixed strings. Treat each pattern specified as a
string instead of a regular expression. If an input line
contains any of the patterns as a contiguous sequence of bytes,
the line shall be matched. A null string shall match every line.
-v Select lines not matching any of the specified patterns. If the
-v option is not specified, selected lines shall be those that
match any of the specified patterns.
Portanto, -F nos permite evitar o escape de . , que, de outra forma, corresponderia a qualquer caractere. -v é a maneira clássica de informar grep para inverter a correspondência.