Antibiotic resistance of Staphylococcus epidermidis and S. warneri
Here some studies concerning the antibiotic resistance of Staphylococcus epidermidis and Staphylococcus warneri:

Antibiotic resistance patterns of coagulase-negative staphylococcus strains isolated from blood cultures of septicemic patients in Turkey - Koksal, Yasar &amp; Samasti [2009]

The abstract of the study above reads as follows:


  The aim of this study is to determine antibiotic resistance patterns
  and slime production characteristics of coagulase-negative
  Staphylococci (CoNS) caused nosocomial bacteremia. A total of 200 CoNS
  strains were isolated from blood samples of patients with true
  bacteremia who were hospitalized in intensive care units and in other
  departments of Istanbul University Cerrahpasa Medical Hospital between
  1999 and 2006. Among 200 CoNS isolates, Staphylococcus epidermidis was
  the most prevalent species (87) followed by Staphylococcus
  haemolyticus (23), Staphylococcus hominis (19), Staphylococcus
  lugdunensis (18), Staphylococcus capitis (15), Staphylococcus xylosus
  (10), Staphylococcus warneri (8), Staphylococcus saprophyticus (5),
  Staphylococcus lentus (5), Staphylococcus simulans (4), Staphylococcus
  chromogenes (3), Staphylococcus cohnii (1), Staphylococcus schleiferi
  (1), and Staphylococcus auricularis (1). Resistance to methicillin was
  detected in 67.5% of CoNS isolates. Methicillin-resistant CoNS strains
  were determined to be more resistant to antibiotics than
  methicillin-susceptible CoNS strains. Resistance rates of
  methicillin-resistant and methicillin-susceptible CoNS strains to the
  antibacterial agents, respectively, were as follows: gentamicin 90%
  and 17%, erythromycin 80% and 37%, clindamycin 72% and 18%,
  trimethoprim-sulfamethoxazole 68% and 38%, ciprofloxacin 67% and 23%,
  tetracycline 60% and 45%, chloramphenicol 56% and 13% and fusidic acid
  25% and 15%. None of the strains were resistant to vancomycin and
  teicoplanin. Slime production was detected in 86 of 200 CoNS strains.
  Resistance to methicillin was found in 81% of slime-positive and in
  57% of slime-negative strains. Our results indicated that there is a
  high level of resistance to widely used agents in causative
  methicillin-resistant CoNS strains. However fusidic acid has the
  smallest resistance ratio, with the exception of glycopeptides.
  Additionally, most S. epidermidis strains were slime-positive, with
  statistically significant (p&lt;0.001) association between methicillin
  resistance and slime production.


The other two studies contain information on the aforementioned strains with regards to penicillin susceptibility.

Antibiotic-resistant Staphylococcus epidermidis in patients undergoing cardiac surgery - Archer &amp; Tenenbaum [1980]

Clinical significance of Staphylococcus warneri bacteremia - Kamath, Singer &amp; Isenberg [1992]

In addition, I would recommend to acquaint yourself with Google Scholar for these kind of questions. It normally makes for a good starting point.