ha guatama,
its so heartening to see mahakavi in your profile pic. its only that which inspired me to post this.
for simplicity let us break this down to two parts. the PE credit spread and the CE credit spread. lets consider PE and you can apply the same concept to CE as well
theoretically. your short PE 10850 when the month expires at your upper PE strike 10500 can loose 350 points (10850-10500)
since you already collected 157 points you can loose only 193 points (350-157) .. but you already expended 67 points by buying 10500 PE, so you could loose a maximum of 260 points. (193+67)
however you already got a credit of 160 points from CEs and you will retain that too, so you only stand to loose 100 points (260-160). hope this helps.