The emergence of vancomycin-resistant organisms means that it is increasingly being displaced from this role by linezolid and daptomycin. However unless you know through culture and susceptibility testing what microorganism you are dealing with suggesting a specific antibiotic therapy is premature.
The difference between oral and IV vancomycin resides in the use of the drug and not a chemical difference. It is a large hydrophilic molecule which partitions poorly across the gastrointestinal mucosa. The only indication for oral vancomycin therapy is in the treatment of pseudomembranous colitis, where it must be given orally to reach the site of infection in the colon.
First make sure to have the microorganism identified, it’s susceptibility found and then have your physician figure out the best course of treatment.