the only time you dont get match bonus is when you leave the match earlier
I stay for the full game. In infected I score let's say 500 points, but then a match bonus of 600 will appear. It won't give me 600 points. Only gives me 500 for the game.
oh lol your getting confused lol, at the end when you go to the lobby and you push the select button once in the lobby it will bring up the match summary from there you can see what you have earned it should look like this
Match Score- XXXXXXXXXXXXXX
Match Bonus- XXXXXXXXXXx
Total Xp earned- XXXXXXXXXXXXXXXXX
^^^^^^^^^^something like the that
It does look like that, but next to match bonus it says 0, and when the match ends it says in yellow text above the team scores your bonus. This does not match up with what I see in match summary.
next time take note of how much xp you earned in total ingame and what the bonus you got, then take note of what the game summary is showing as your total XP earned if they match that means the games is screwing up and its including your match bonus into your match score