Ulysses is a local, so his information is probably as good as you're going to get, but I thought I'd add a few things.
I've marked a series of points on
this map
A - Probably dry
B - Might be water, but if dry, head north on the trail to Taquitz meadow
C - This creek bed is usually dry, but ...
D - This spring about 20 or 30 feet to the right (east) of the trail is very reliable. It's recessed into the ground and is hard to spot, but look for signs of people going to the spring. It's just on the fringes of the meadow.
E - Probably dry
F - Low flow, but there should be water
G - Probably dry
H - Probably has water
Not on the PCT, but since you're going to the peak:
I - Frequently there is water here
J - There's a little pool just above where the trail crosses the creekbed. This is the best place to get water in Little Round Valley
K - Little Round Valley -- Frequently there's water in the meadow although I think the above mentioned pool is a better place to gather water.
Hope that helps,
HJ