You seem to have some doubt about the ability of the WTB DX-23 rims to handle 115PSI. Personally I'd think your V-brakes put out more force than that from the outside. Brake boosters were introduced to reduce frame spreading by V-brakes so there are high loads on the rim walls regardless of the tire pressure inside.
I'd suggest your real issue was insufficent spoke tensioning - part of normal wheel maintenance, compounded by poor road conditions and possibly your weight - which you haven't yet mentioned. This was described as a 'new bike'. Was that 'brand new with warranty' or just 'new to you'?