http://stackoverflow.com/questions/30822627/error-handling-for-zipped-observables?noredirect=1#comment49693567_30822627

gistfile1.java

public class Main {
    public static void main(String[] args) {
        ContentManager cm = new ContentManager();

        Observable
                .from(cm.getPermalinks(10))
                .flatMap(permalink -> Observable.zip(
                        Observable.<Content>create(subscriber -> cm.getDataByPermalink(permalink, new SubscribingRestCallback(subscriber))),
                        Observable.<Content>create(subscriber -> cm.getStreamByPermalink(permalink, new SubscribingRestCallback(subscriber))),
                        (dataContent, streamUrlContent) -> {
                            return new Content(dataContent.permalink, dataContent.logoUrl, streamUrlContent.streamUrl);
                        }).onErrorResumeNext(Observable.empty()))
                .subscribe(System.out::println);
    }
}

class SubscribingRestCallback implements RestCallback {
    private final Subscriber<? super Content> subscriber;

    public SubscribingRestCallback(Subscriber<? super Content> subscriber) {
        this.subscriber = subscriber;
    }

    @Override
    public void onSuccess(Content content) {
        subscriber.onNext(content);
        subscriber.onCompleted();
    }

    @Override
    public void onFailure(int code, String message) {
        subscriber.onError(new Exception(message));
    }
}