It's better but not fixed and it introduces some seams that weren't there before. I understand that you can't reproduce it...you would have to render it on a mobile device with transparency and mipmaps enabled and it might differ from gpu to gpu in strenght too. Anyway, i try to explain what i had in mind to fix it based on this image:
At the moment, the mapping starts with the bottom of the trunk mapped with the bottom of the texture and then it goes up like the red arrow to the left shows. Then it flips to the right side (mapping wise) and maps from the top of the tree down to the end of the red arrow. Where they both meet, the problem occurs. Simply because the bilinear filter starts to blend in parts of the upper half of the texture, which is transparent (or white in this case). My idea was to "simply" limit the u/v coords so that they don't go all the way up (or down) like the red arrow does but do it like the green arrow shows. There won't be a seam that way and no accidental blending with the upper half either.