Glycosyltransferase that transfers an L-rhamnose moiety from dTDP-L-rhamnose to the elloramycin aglycone 8-demethyl-tetracenomycin C (8DMTC) in elloramycin biosynthesis, an antitumor polyketide. Possesses donor substrate flexibility: able to transfer at least 11 different sugars to 8DMTC, such as NDP-D-glucose, as well as NDP-L-digitoxose, including both L- and D-isomeric forms of some sugars. 8-demethyltetracenomycin C + dTDP-beta-L-rhamnose = 8-demethyl-8-alpha-L-rhamnosyl-tetracenomycin C + dTDP + H(+) Antibiotic biosynthesis. Belongs to the glycosyltransferase 28 family.