A cleric on the Material Plane wields a weapon with the magic weapon special ability ghost touch. That cleric casts the spell ethereal jaunt. Can the cleric attack corporeal, non-ethereal creatures on the Material Plane with his ghost touch weapon?
Incorporeal and ethereal are different things, even though there is obviously a lot of overlap. But ghosts, for example, deal with the two things separately: in its ordinary state, a ghost is ethereal (that is, residing on the Ethereal Plane), but it can manifest:
When a ghost manifests, it partly enters the Material Plane and becomes visible but incorporeal on the Material Plane.
The ability goes on to clarify many of these issues, including notes that a manifested ghost (and only a manifested ghost) can use ghost touch items. If it’s not manifested,
it cannot affect or be affected by anything in the material world.
That includes ghost touch items.
Libris Mortis even includes a section on page 143 entitled Incorporeal vs. Ethereal, which begins by saying
Many people confuse these two terms. Some of this confusion revolves around the ghost, which can be both ethereal and incorporeal, depending on whether it is manifested.
This section explicitly calls out ghost touch items as being unavailable to ethereal creatures:
Even most of the limited options available to an incorporeal creature—such as ghost touch weapons and armor—don’t work for an ethereal creature
No, That Doesn't Work
Unlike incorporeal creatures, ethereal creatures are not present on the Material Plane...
An ethereal creature can’t affect the Material Plane, not even magically.
For reference, the blink spell talks about how to reduce the penalties for attacking the warded creature, and that you apparently can't mitigate the 20% miss chance.
Force effects and abjurations affect you normally. Their effects extend onto the Ethereal Plane from the Material Plane, but not vice versa. An ethereal creature can’t attack material creatures...
Since you are using a spell, we need to first check the spell text in question, and the spell you referenced has the following in the description:
An ethereal creature can’t attack material creatures, and spells you cast while ethereal affect only other ethereal things.
Thus while the other answers (correctly) point out that in general ethereal sources cannot attack material targets (with the obvious exception of a ghost using the manifest ability, which causes it to exist on both the Ethereal and Material planes simultaneously), it is always possible that your spell might contain exemption text. Unfortunately, the spell instead agrees with the general rule for ethereal creatures.
It is also worth noting that in the Ghost Touch description, it only references incorporeal related effects, never once ethereal.
You could always use the spell research rules to develop a spell that works otherwise....