Your DXB-BKK-DXB flight is a EK flight, so you would need to check with your host FF scheme to see if 1)-EK flights accrue points and 2)-EK codeshare flights accrue points. I know UA has some sort of M+ agreements with EK, but not sure of anyone else.

As for lounge access, you might have access if TG is listed as an operating carrier on your boarding pass & you have your host FFP *G card, as access can be gained by flying a "same day departing * Alliance member carrier operated flight". Operated flight being definitive wording.

Having said that, the only *G lounge option at DXB is LH - notoriously strict, so they may have issues with a BP holding a EK flight number and their interpretation of the above wording in access rules.
Also I'm not not sure if they are open that early in the evening. (Their flight to FRA is middle of the early hours [0130-0300 pending time of year] but the TG flight to BKK departs mid evening.)
Someone is bound to have been through there lately and can advise.