No, Sultai Ascendancy does not interact with cards that care about surveil. Surveil is a specific keyword ability defined in rule 701.41. Cards that trigger when you surveil only trigger if the instruction contains that keyword. The oracle text of Sultai Ascendancy describes an action that is the same as surveil, but it does not use the word "surveil".
It doesn't look like it does. Surveil is a keyword, and while it didn't exist when Sultai Ascendancy came out, it does not appear on the Oracle card text either. Sometimes, old cards do get updated when new keyword (compare for example the Oracle and the Printed text for the Alpha Edition Serra Angel), but it did not happen in this case. Therefore, Sultai Ascendancy's ability isn't keyworded Surveil and your Dimir Spybug won't profit.