How does the IES5206 work with ADSL2+ bonding?

Topology:

Internet ------IES5206-------SBG3500-N000 ------PC

Configure the following on the IES5206:

dsl channel-profile test
   tpstc-adsl ptm
exit

dsl line-profile test
   transmission-type adsl2+
exit

dsl line-template test
   channel-profile test
   line-profile test
exit

interface vdsl 1-1
   line-template test
   gvector disable
exit

interface vdsl 1-2
   line-template test
   gvector disable
exit

interface vdsl 1-49
   gbond-member 1,2
   vlan trunk uni-untag svlan 1 spbit 0
exit

Configure the following on the SBG3000-N000: