11:15-16 Is this the same scourging in the temple as Matthew records?

Yes (cp Mt 21:12-13). This is the same scourging as recorded in Mk 11.

It is the second scourging in the temple by Jesus and took place when He went up to Jerusalem the day after He was at Zaccheus' house (cp Mt 21:1-16; Lk 19:1-11, 28, 41-46). Jesus' first scourging in the temple is recorded in John's Gospel.

It took place within a week or so of Jesus commencing His earthly ministry, a few days after the wedding at Cana where He performed His first miracle - turning water into wine (cp Jn 2:1-17). This was three days after Jesus commenced His earthly ministry (cp Mk 11:1 with Mk 1:35-51).

After Jesus' second scourging in the temple in Mt 21 and Mk 11

He went to Bethany and lodged with Lazarus - who He had raised up from the dead - and Martha and Mary, His sisters (cp Mt 21:17; Mk 11:11; Jn 12:1-2). The third scourging took place the very next day (cp Mk 11:12-16).