Hmm higher than mine. I thought they would be the same, but I've never had or seen a Titan X overclock.
That said IIRC SLI makes overclocking a bit more difficult. So that might be the limiting factor.
You can safely go up to +37mV btw.

I bump the clocks up then run Heaven bench maxed out settings to check for stability. The power limit is a balancing act... for me running the fans at max speed eats up 2% of my power limit.. But keeping the chip cooler helps with stability. In your case you are water cooled so that helps a bit.
I think the memory is fast enough already, focus on the core overclocks first then tweak the memory. Then fine tune to prevent throttling under full load. Kinda fun actually!

That's how I settled on my overclock of 1200Mhz core, 1560Mhz memory at 1237mV fan @ 67% using the EVGA PrecisionX overboost voltage.