The current PhoneGap plugin implementation doesn't have this functionality implemented, however it very simple to add it, just fork the plugin and modify it to use card.io logo instead of PayPal.
For iOS https://github.com/card-io/card.io-iOS-SDK/blob/master/CardIO/CardIOPaymentViewController.h#L92
For Android http://card-io.github.io/card.io-Android-SDK/io/card/payment/CardIOActivity.html#EXTRA_USE_CARDIO_LOGO
Hope it helps.