Climbing/Bouldering ~2x weekly. How long do these sessions last?
1 Interval session. What's a typical session look like?
1 Strength session. Again, what's a typical session look like?
Are you involved in any other sports?
Do you just want to get stronger for climbing purposes?
Do you climb on set days, or just go when you feel the urge?
It's hard to get stronger, especially for a beginner, on 1 strength session weekly. Not impossible, but hard. This is really because frequency and working on the skillful execution of the movement is important for the neophyte.
The climbing is really high volume relative strength training coupled with practicing skilled movements, especially in relation to upper body strength.
I suspect that you're going to have to lower your intensity range (the 90%) and increase volume in the movements you're interested in getting stronger in.