My question: example: there is an iPhone on sale with the current bid at $150, my max snipe is set to $200. Does Myibidder bid $151 or $200?

There is no need to submit your question multiple times. It will not speed up the response anyway.
Here is the copy of my original response in case if you deleted it:
The sniper will put the amount you specified. If nobody bid higher, you will win at the lowest possible price just enough to outbid the previous bidder by one increment only.