Biologically active bacterial cellulose (BC) was efficiently synthesized in situ using wine pomace and its hydrolysate. The structural and biomechanical properties together with the biological functions of the BC were investigated. Functional BC from wine pomace and its enzymatic hydrolysate were of high purity and had higher crystallinity indexes (90.61% and 89.88%, respectively) than that from HS medium (82.26%). FTIR results proved the in-situ bindings of polyphenols to the functionalized BC. Compared to BC from HS medium, wine pomace-based BC had more densely packed ultrafine fibrils, higher diameter range distributions of fiber ribbon, but lower thermal decomposition temperatures, as revealed by the SEM micrographs and DSC data. Meanwhile, wine pomace-based BC exhibited higher loads in tensile strength and higher hardness (4.95 ± 0.31 N and 5.13 ± 0.63 N, respectively) than BC in HS medium (3.43 ± 0.14 N). Furthermore, BC synthesized from wine pomace hydrolysate exhibited a slower release rate of phenolic compounds, and possessed more antioxidant activities and better bacteriostatic effects than BC from wine pomace. These results demonstrate that BC synthesized in situ from wine pomace (especially from enzymatic hydrolysate) is a promising biomolecule with a potential application in wound dressing, tissue engineering, and other biomedical fields.