Menu -> Friends -> Search -> ID -> Enter ID -> Click portrait -> Scroll down to Guild -> Details
game.granbluefantasy.jp can be replaced with gbf.game.mbga.jp for mobile browser version.

Guild War wins/losses are taken from /gbfg/, and contribution is taken from http://gwresult.imgur.com. I do not guarantee its accuracy. Use at your own risk.
Letter in brackets is the tier they qualified into. Contributing members is next to Wins/Losses. Number outside parentheses made it into top 80k, number inside made it into top 20k.
Due to the new private guild feature added in May, some guilds cannot have contributing members added. These will have (PRIVATE) instead of the numbers described above.

Updated as of June 5th, 2017

Guild name: Lum1
Link: http://game.granbluefantasy.jp/#guild/detail/388489
Profile ID referrer: 5697981
Notable recruitment policies: Recruits via IRC
Last Guild War: Jan 5W-0L : 23(2) | Mar [A] 4W-1L : 29(15) | Apr [A] 4W-1L : 23(7) | May [A] 2W-3L : 22(4)

Guild name: Lumiere★ (Lum2)
Link: http://game.granbluefantasy.jp/#guild/detail/401211
Profile ID referrer: 5974596
Notable recruitment policies: Recruits via IRC
Last Guild War: Jan 3W-2L : 16(4) | Mar [A] 4W-1L : 23(5) | Apr [A] 4W-1L : 15(5) | May [A] ?W-?L : 11(4)

Guild name: 小さな女の子 (Little Girls)
Link: http://game.granbluefantasy.jp/#guild/detail/432330
Profile ID referrer: 6823403
Notable recruitment policies: Unknown
Last Guild War: Jan 4W-1L : 18(3) | Mar [A] 3W-2L : 18(3) | Apr [A] 3W-2L : 25(5) | May [A] 4W-1L : 17(6)

Guild name: 萌え兄弟団 (Moebros) (Dead; included for historical reasons)
Link: http://game.granbluefantasy.jp/#guild/detail/438850
Profile ID referrer: None

Guild name: Haruna
Link: http://game.granbluefantasy.jp/#guild/detail/472465
Profile ID referrer: 7665662
Notable recruitment policies: Unknown
Last Guild War:Jan 3W-2L : 20(4) | Mar [A] 1W-4L : 12(4) | Apr [A] 2W-3L : 19(6) | May [A] 3W-2L : 16(7)

Guild name: NoFlipCity
Link: http://game.granbluefantasy.jp/#guild/detail/518173
Profile ID referrer: 8011166
Notable recruitment policies: Unknown
Last Guild War: Jan 1W-4L : 15(3) | Mar [A] 4W-1L : 12(1) | Apr [A] 3W-2L : 12(3) | May [A] 2W-3L : (PRIVATE)

Guild name: AllRounder (Dead; included for historical reasons)
Link: http://game.granbluefantasy.jp/#guild/detail/571528
Profile ID referrer: None

Guild name: Dem Bois
Link: http://game.granbluefantasy.jp/#guild/detail/705648
Profile ID referrer: 13032389
Notable recruitment policies: None
Last Guild War: Jan 1W-4L : 9(0) | Mar [B] 3W-2L : 9(2) | Apr [A] 0W-5L : 4(1) | May [A] 3W-2L : 12(0)

Guild name: COWFAGS
Link: http://game.granbluefantasy.jp/#guild/detail/841064
Profile ID referrer: 10252969
Notable recruitment policies: Rank 101+ only; must play daily and join the Discord
Last Guild War: Jan N/A | Mar [A] 0W-5L : 6(1) | Apr [A] 1W-4L : 10(2) | May [A] 2W-3L (?) : 10(1)

Guild name: Granseﾒual
Link: http://game.granbluefantasy.jp/#guild/detail/845439
Profile ID referrer: 13675529
Notable recruitment policies: None
Last Guild War: Jan N/A | Mar [B] 3W-2L : 4(0) | Apr [B] 2W-3L : 1(0) | May [B] 1W-4L : 3(0)

Guild name: Bullies
Link: http://game.granbluefantasy.jp/#guild/detail/745085
Profile ID referrer: 6914026
Notable recruitment policies: None
Last Guild War: Jan N/A | Mar [B] 1W-4L : 4(0) | Apr [B] 3W-2L : 4(1) | May [A] 0W-5L (?) : 6(0)

Guild name: Aion no Me
Link: http://game.granbluefantasy.jp/#guild/detail/645927
Profile ID referrer: 11814116
Notable recruitment policies: Must join and use the Discord
Last Guild War: Jan N/A | Mar DNQ | Apr [B] 4W-1L : 3(1) | May [B] 3W-2L : (PRIVATE)

Guild name: TOOT
Link: http://game.granbluefantasy.jp/#guild/detail/844716
Profile ID referrer: 14417356
Notable recruitment policies: Rank 70+ only; must join the Discord
Last Guild War: Jan N/A | Mar DNQ | Apr [B] 2W-3L : 3(0) | May [A] 0W-5L : 6(0)

Guild name: Fleet
Link: http://game.granbluefantasy.jp/#guild/detail/599992
Profile ID referrer: 8817744
Notable recruitment policies: None
Last Guild War: Jan N/A | Mar [B] 1W-0L : 1(1) | Apr [A] 0W-5L : 3(2) | May [B] 0W-5L : 1(0)

Guild name: Beafriends
Link: http://game.granbluefantasy.jp/#guild/detail/940700
Profile ID referrer: 6683855
Notable recruitment policies: Must love Beatrix
Last Guild War: Jan N/A | Mar N/A | Apr DNQ | May DNQ : 0(0)

Guild name: BellaBarca
Link: http://game.granbluefantasy.jp/#guild/detail/977866
Profile ID referrer: 14979189
Notable recruitment policies: None
Last Guild War: Jan N/A | Mar N/A | Apr N/A | May [B] 1W-4L : 2(0)