I see no reason for blooms for Clever or French Press. Once water is introduced to the coffee, it in effect, starts the brewing/steeping process. A gentle stir helps just after the final water is poured, assuring all grounds are wet and have contact with water.
Here's my understanding of the issue and the reason we bloom our Clever drippers in our shop. Agitation & even saturation: Blooming a clever or press pot for 30 seconds or so allows the coffee to off-gas and break down the "force field" that the rapid release of CO2 forms around the coffee immediately after being hit with hot water. Once that force field is broken down, agitation from introducing the remainder of the brew water is a much more significant factor. It also allows for an easier saturation of all of the coffee grounds without the pockets of dry grounds that will sometimes occur with very fresh coffee. As Jason said, this can be accomplished with a stir, but stirring also introduces room temperature air, which cools the slurry. If complete saturation and a good amount of agitation can be accomplished without a stir, I think it's much more desirable.
The "force field" analogy is nice - as long as gasses are escaping there's less extraction, regardless of what method is being used (except high pressure ones). For that reason, something really ought to be done early in the process to break up the crust and move things around to uniformly saturate the grounds.
I agree that a post-fill stir accomplishes the same thing as a bloom then fill in a pourover (or partially plunging a french press). A stir may give you more direct control of the agitation, though, since its be done with a spoon or whisk. Compare that with agitation with pour, where variables like speed, spout, pouring location, and height all play into the degree of agitation. I'd think a stir would give you greater consistency - which is a real benefit for guys like Jason that travel all over brewing (and teaching how to brew) in these devices.
Roman's point about temperature is well made though - having a second addition of water allows you to warm the slurry back up, and if you aren't careful with your stir you can cool things down substantially. You probably need to accommodated this by increasing your starting temp slightly.